I removed my are to in my 1998 s70 volvo . anyone have advice ?

 

is it the original unit that came with the car? if so, a dealer can give you the code from the VIN. If the car is used and you are not sure, I'd pull the radio out to see if its written on top or somewhere in the owners manual or on a note in the glove box etc. should be four digits 1-6.