If you have a helper (or if you're very coordinated and careful), you can very likely lift up the logic board far enough to replace both RAM modules without pulling the logic board all the way out. Just be careful what you touch, of course.
Cutting through this extra adhesive on the bottom took a bit more effort than the step and picture implied (to me). Unlike the other edges, here don't be afraid to really push the card in there to break the seal, there's nothing behind that adhesive that is breakable.
