On the Volvo key fob remotes most of the time the housing brakes but the electronics still work fine and Volvo only sells the entire remote and not the housing separately. Plus if you purchase a new key fob from Volvo you also need to have programming to mate the new remote up with your car. This is typically an expensive replacement.
This cover will work with all four button remotes up to 2004 that do not have the Key Integrated Remote (KIR.)
Disassembly is easy. Simply remove the T9 screw and separate the housing. Remove the electronics and place them in the new key fob cover and join the two halves.
While you have your remote disassembled, it's also a good time to replace the battery.