I was married to my ex-husband 31 years. we have both remarr

I was married to my ex-husband 31 years. we have both remarried. While married I'm sure "we" paid on his life insurance. Can I request to stay on his policy as his soul survivor beneciary? Would he have been able to have removed me and put his present wife as soul benificiary? Would that have been legal without my signature? Can I force him to put me back on his SSB? I will not have any retirement. Plese help!