How do get rid of those callus' on your hand?

Okay so I used to do gymnastics and I always had callus' on my hands from the bars. So now my hands are all, hard, and bumpy I guess. I stopped gymnastics a while ago, but there are still sort of bumps, and it annoys me because I don't even use the bars anymore, and I lotion them, and the other day my friend and I were arm wrestling and she said my hands were all callus... it's really annoying and I wan't my hands to be soft like a girl's hands should be... so what can I do to make my hands soft? Thanks a lot!