I don't work I haven't in 2-4 years. I started getting ssi last year I have 4 kids I filed for a divorce feb 2008 still pending my soon to be ex filed without me and got all the tax money he also got the extra I guess you call it stimulus the checks were in his name.. I was told I can file and get a return also... please tell me how

If he claimed them on his tax then you can not.
You can go after him for claiming them when you could have.

Tell me how I go about going after him and do I still have time or is it to late

This link to IRS may help you.

Stimulus Payments: Instructions for Low-Income Workers and Recipients of Social Security and Certain Veterans' Benefits