How to claim 2 vehicles that where gifted upon the decedents death that the executor won’t honor and there is a probate

I was the executor of the estate and the daughter of the dependent tricked me into signing a declaration to give to my rights as executor. I Gave her and her attorney the letters left by the descendent to me gifting me his 2 vehicles. The executor refuses to acknowledge the documents and took possession of one of the vehicles. What do I file to put a claim I. For the vehicles? I can’t seem to get any assistance from the court due to closure and Covid 19 and left messages and send an e mail with no response. I was told by a friend to file a creditors claim but don’t know how to do it correctly. Does your office help with this? Can’t afford an attorney and I am senior. I just need someone to tell me what I can do to correctly put in the proper information to the court to claim the vehicles before it’s too late. I also called Legal services with Humboldt county and they don’t assist regarding probate. Thanks an advance