How do I file a claim in this situation??

My husband is trying to convince me about filing a claim against another insurance company following a new law passed of late. This company has got associated with an accident where I was rear-ended but resulted in a depreciation being caused to my 2001 Rodeo. Now, I am yet to learn about the different procedures in order to go about this claim-filing. I'm sure you guys would help me get my deserved claim.