Removing Weight from Small Cellphone Vibrator Motors

Robots nowadays are getting smaller and smaller. I wanted to make a very small mobile robot. I found out that cellular phone's vibrators are tiny motors but with unbalanced "weight" at its end rotating. These tiny motors have strong torque and just fit for my purpose. But removing the "weight" is difficult.

I wondered how to remove the "weight" on small cellphone vibrator motors. Forcing it may damage this fragile motors. I tried to search the net and using Google and found this site Tiny Motor. Now I can start building my tiny bot.