estimate on atv parts?

hi, my friend and i were in my woods/backyard and my friend spotted a quad that had looked like it had been outside for weeks. him and his friend began pushing it down a hill and then i did too. then he wanted to hot-wire it. He used my tools and carved the seat open and the side of the plastic things that cover the top of the wheels to say mine now with a utility knife. I took off the part that goes around thing that tells you your mileage on the quad. he cut the ignition part where you put the key in and turn it, leaving it useless. All i did was push the ATV and take that part. so after two weeks of it being there the person that owns it finds it and tells my friend who tells him my name and number because i had told him about it before. His dad calls me (the kid is a senior in high school) saying the vehicle was stolen and vandalized. So i said my friend did most of the damage. All i did was push it and take off the receiver that is around the meter which was broken anyway. Now he wants me to pay for the damages and split the amount of pay with my friend which is totally unfair considering i didn’t do anything. I need an estimate, for a Yamaha grizzly 600 that looks like its pretty old, but like i said i need an estimate on how much the parts would be. my mom said if she(meaning me) has to pay(with my money) more than 500 dollars that i am in big trouble. PLEASE HELP ME!! i NEED an estimate because i still have to push that damn quad uphill with my friend to back where we found it so this kids dad can bring it to a place to get it fixed and get an estimate on how much that all will cost. thank you very much

Tagged as: Atv, Atv Parts, big trouble, dad, Damages, hot wire, mileage, mom, Money, quad, utility knife, Wheels, yamaha grizzly 600