ATV In both names

Okay I have a quick question regarding this. We have an ATV that is in both of our names. I do not have possession of this he has it. Since he got mad at me he told me that he is no longer going to pay this and that it’s now my responsibility. I have a very high credit score and do not want to destroy my credit but I honestly dont’ want to pay it. What can be done to get this out of my name? Is there anything or am I stuck with this bill? He doesn’t give me anything for child support and I am stressed beyond belief. I have already paid a bill for him because somehow my name got on it for advertising for his company. He told me he wasn’t paying that also and I ended up paying it so that I don’t ruin my credit. Please advise me. Thank you so much in advance.

He will either need to refinance the loan on the ATV, or the same needs to be sold and the loan paid off.
I suggest you contact child support enforcement to have the process to begin child support started right away.