My question involves education law in the State of: Florida

I need some help....
My mother cosigned a loan for sallie mae for a very close friend our ours, and now he is basically disappearing, has not paid for 4 months, we cannot get a hold of him, they are wanting her to pay...this is becoming a huge issue that was never expected due to the nature of the friendship.
Does anyone know if there is a way to get out as a cosigner with sallie mae?
how would you go about doing this?

They are not very helpful in this matter.

please help!