My phone shut down and I forgot my password and now I can't use it how can I restore it?? It's a sgh-t629 from t-mobile??

Call your airtime provider and they will assist.

Samsung phones have over-rides on that, however there is a possibility of erasing everything on your cell phone when you do any type of reset. I would recommend calling your cell phone provider and asking for a custom reset. The custom reset may not delete all your information like a full reset would. :)