I need help with my 2003 yamaha blaster i need help fixing it.?

i dont know jack about quads. my brother told me the pistons are f'ed up he was going to fix the quad but he moved to florida. so i need to replace the pistons so my dads going to buy a blaster pistons kit thing. but idk how to take the engine out or how to access the pistons.. i mean im sure i cud try to do it without any help but im sure it will end in disaster. please help me