Answer:
Hi (friend's name),
Everyone in school knows that you've been suspended for truancy. I know it might appear as something unfair, but just listen to what I have to say.
You and I both know that your reasons of missing school haven't been valid. I completely understand that you dislike school and would rather stay at home. I really think that you should consider changing and turn a new leaf. Turn the page of this chapter in your life.
I want to see you in school again, accomplishing great things. Know that I'll be here for you and always been been. Through thick and thin I'll be here. When you return to school I'll help you out and get you back on track.
Your friend,
(Your name)
Step-by-step explanation:
I hope you like it, I tried my best.