Tail light condensation / gasket info?

So, I've got the tail light condensation (left assembly), I pulled it out today and tried the hair drier thing, but aside from blowing a circuit breaker in my house, it didn't seem to do much good. I could get it to evaporate, but it condensed back when I took the drier off.

I was considering doing the drilling thing, but I'm not sure I'm comfortable drilling the plastic.

What I'm wondering is: how do you take the red plastic part off from the black assembly? There are little clips, but I can't figure out a way to release them / get the red part off.

Also, does somebody know the part number for the replacement gasket? The one I'm looking for is the one that I assume is enclosed in the red plastic part (the gasket that is immediately accessible when you pull the assembly is in good shape).

Any help.. please?