Nokia 6600 update at home

hello sir.......i am using nokia 6600....once due to some virul problem from a specific application....the phone encountered a Os problem.......now the phone's condition is such that when i switch on the mobile...it gets on....but all its fumctions gets disabled.......for example....if i press the menu key ....it doesnt respond......but it doent mean dat the key doesnt work...
This is the third time that i got it repaired from mobile repair shops....but am having a pc and waana do it myself at home.......am also using internet conn.at home..............so could u pls tell me the process of updating a nokia 6600 phone?.....it doesnt hav any usb connections....so is there any gadget that can be used to connect 6600 and a pc....