how to repair an mp3 player jack?

hi sir,i had a sony zappin mp3 player(4GB)...from past few months its not acting good....i thought may theres a problem with the headphones i had but i changed them many times but no effect on it....so it the mp3 player jack which is causing trouble...i tried opening it.....but there is something in this (sony zappin mp3 player) that i m unable to open it....please help me out...i love listning songs and i can't live without them.......and this player is my life and last hope...please help me out..if any way like audio video or any thing u can come up with will be alot helpfull to me..and if nothing then you can simply just guide me instruction and i will do it myself.....but please guide me to specifically this(sony zappin mp3 player) player.

thanks.....