I guess I would have answered my own question with time. The headlight is almost too big for my oven anyways. A heat gun and vice grips is definitely the way.
I would also say to have some epoxy around to fix the screw tabs that will probably break off from the inner gray shield where the screws come through from the back into the lens. You can't see them so not a big deal.

Try to heat the butyl caulk up as much as possible before adding it in the groove of the headlight assembly. You probably don't need much more than just filling the groove. Adding too much makes it harder to get together. Pinch the lens to the headlight assembly with vice grips and a ratchet strap would probably work pretty good as well.

When reinstalling, I would leave all the headlight screws out until you get the brace/bracket put back in from under the inner fenders. I would also say to loosen all of the surrounding bolts from up top around the light and including the fender to help the bracket to go back in the track easier.

Also make sure you clean the top lip of the bumper (Where the bottom of the lights sit) because you can see the dirt through the bottom of the lens after installed.

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2007 (12/2006) X5 E70 3.0si / ZF GA6HP19Z