HOW CAN I MEND A STUFFED DOLL?

I have offered to (try) to mend a stuffed doll for a friend, but now I am unsure how to go about it!

Apparently, the seam at the back of the doll was ripped open by Customs Officers on arriving back in the country. They refused to believe that the bag of sand (used as an internal weight which showed up on their x - rays) was not something more suspicous & ripped the back seam! Now the doll is in a sorry state withfluff & a bag of sand needing to go back inside.

Help!!!

Claire