Originally Posted by trigga_b
Dam imidazol, you just brought faith back to my bonneville. Thanks for the pics. I never got around to looking for it because it'* cold as H*** out here, so I just parked and was going to sell it for $800. The first day I told someone they was thirsty to buy it, but I didn't want to sell it right away.
Fast68 has a good outline of the steps. I'd guess the hard part is getting the hoses off under the hood. It requires a long reach on a special side tool to get to the clamps on the hoses over the tubes sticking through from the heater.
Someone who had done it sounded like it'* a matter of sealing the core so air doesn't bypass when you reinstall it. Have some caulk like sealer. Note that cover has two screws holding it and has clip slots holding it on the back end.
Having spent some quality time troubleshooting a programmer on my 98, I've laid on the seat and floor long enough to know it'* not pretty, but when the globebox is off, it'* easier to get to than it seems.
I'd recommend doing it on a warm day so the caulk on the cover and the heater core are softer for removal.