A crowbar will work, but that's not the recommended method...
Seriously, you should pick up a Chilton's or something for your vehicle.
Or at least find a forum that has to do with Chevy's..or even better, Monte Carlos.
This is a CarPC Forum. As far as you've mentioned, you aren't installing a CarPC.
I didn't see Monte Carlos listed, but this might be a good place to start...
1998 Volvo V70 "Volputer"
Worklog: planning and procurement.