Keeping animation clips when re-importing .FBX

Hello,

I'm working with a character that is animated in MAYA. I import the character into Unity via FBX. I then convert to Legacy Animation Type. Then, I set my clips up by naming them and specifying a frame range.

New animation is done on the original character. I want to re-import the character and continue to add to my clip list.

I have not been able to figure out how to keep my current clips, and just add to them with a new version of the character. It seems like the original frame range for the character is locked.

Thanks!