Note: Just based on Qur'an convincing them is difficult, because they don't believe, but just remind them about the truth if they fear the Father.
I guess this answer is still open because the question asks the verses from Qur'an as a help in an attempt to prove that Jesus(pbuh) is not God, rather than focusing on how to prove Jesus(pbuh) is not God simply. As described above, I won't discourage you that Christians are not going to believe you no matter how many verses from Qur'an you show it is of no use, I encourage you by trying to help you accumulate verses from the Qur'an to show them. And most importantly, your job is to just remind them of the truth that's it. You won't be asked why did you fail to convince them, if they had to become Muslims, surely God would have guided them all. So, let not their refusal stop you from warning.
Firstly, shaitan promised he would misguide people and take them along with him to hell.
There is no God but one God the Father, who created everything including Jesus (pbuh).
And your god is one God. There is no deity [worthy of worship] except Him, the Entirely Merciful, the Especially Merciful. (Qur'an 2:163)
He is not God, as he is relying on his father for everything.
Next, Jesus(pbuh) said
Indeed, Allah is my Lord and your Lord, so worship Him. That is the straight path." (Qur'an 3:51)
The same thing is there even in Bible emphasizing the worship of Lord God.
Again the same thing is repeated in Qur'an
They have certainly disbelieved who say, "Allah is the Messiah, the son of Mary" while the Messiah has said, "O Children of Israel, worship Allah , my Lord and your Lord." Indeed, he who associates others with Allah - Allah has forbidden him Paradise, and his refuge is the Fire. And there are not for the wrongdoers any helpers. (Qur'an 5:72)
This time more clear to those who say, Jesus is God, or God is Jesus.
This further helps us understand that Jesus did not have divinely nature.
The Messiah, son of Mary, was not but a messenger; [other] messengers have passed on before him. And his mother was a supporter of truth. They both used to eat food. Look how We make clear to them the signs; then look how they are deluded. (Qur'an 5:75)
Say (O Muhammad SAW to mankind): "How do you worship besides Allah something which has no power either to harm or to benefit you? But it is Allah Who is the All-Hearer, All-Knower." (Qur'an 5:76)
Everywhere in the Bible, Jesus(pbuh) focused on the word "The Father", emphasizing Allah, rather if he were to be God, then he would've commanded his disciples simply saying, "worship me that's fine. I'll grant you heaven". No, he said, he is the ticket to heaven, to ultimately reach the father, you need to hold fast to me, meaning perfectly follow me to reach the Father. Because Father doesn't like the wrong doing people, Jesus(pbuh) came to guide the lost sheep of Israel, to take them back to the father through him. You can find a near summary of his teachings in Mathew 10, but again there he emphasized on doing righteous deeds by loving him.
Say (O Muhammad SAW): "O people of the Scripture (Jews and Christians)! Exceed not the limits in your religion (by believing in something) other than the truth, and do not follow the vain desires of people who went astray in times gone by, and who misled many, and strayed (themselves) from the Right Path." (Qur'an 5:77)
This clearly warns the Christians don't try to over understand the Bible, but just understand what is clear and precise. Rather don't exceed your limits, don't follow the vain desires of the people who misled many. These words can be clearly attributed to the disciples of Jesus (pbuh) who invented all extra concepts of Jesus(pbuh) being God. In short, I can tell you to advice him to at least follow the Unitarian Christians, who don't say Jesus(pbuh) is God.
No where in the Bible did Jesus(pbuh) implicitly say that 'I'm God'. It is they perceive things which are not clear, there by leading themselves to Fitna.
But the way people perceive things changed over time. At the very beginning, his disciples clearly understood him as the only son of God, later, if he could be son of God, then he is also God. Based on "I and the father are one" as said by Jesus(pbuh) they claim he is god but you need to prove them that this statement doesn't mean Jesus(pbuh) is god, but means 'what ever I say/do, it's because the father has inspired in me'. But the shaitan is sure to deceive people in what ever way possible. He leads them to follow the footsteps of their ancestors and fulfills his promise of taking people to hell. He could ask, Why is that, just believing Jesus (pbuh) is God, so wrong? Then I ask 'why is that just not believing Jesus (pbuh) is God not right? I mean, all you need to do, you can still be a perfect Christian by following him perfectly along with being a near believer just by not believing Jesus (pbuh) is God'.
If they read things clearly from the Bible (Old Testament), any common person with basic understanding could doubt is it not wrong to call Jesus (pbuh) as God based on Old Testament, but unfortunately the reminder of the people delude him.
They are still trying their level best to prove Jesus (pbuh) is God, but all they can do is convince people but can't prove.
Friendly reminder, 2day, most Christians are deluded by the false notions created by the inferences made by the disciples. Although the disciples never themselves talked about the concept Trinity implicitly, later generations created it. So, if you really care for your friend that he/she should not enter Hell, then you need to prove to him/her 2 more things, i.e. Trinity is wrong (Qur'an 5:73), & Jesus (pbuh) being literal or 'only' son is wrong (Qur'an 39:4 & Qur'an 21:26). If you can't prove them these 3 things are wrong, then
O you who believe! Take not the Jews and the Christians as Auliya' (friends, protectors, helpers, etc.), they are but Auliya' to one another. And if any amongst you takes them as Auliya', then surely he is one of them. Verily, Allah guides not those people who are the Zalimun (polytheists and wrong-doers and unjust). (Qur'an 5:51)
Please don't waste your precious time.
May the creator guide us all.