Yeah, it's a serious PITA but it can be done. What I had to do was bend the studs going through the firewall so the booster can be turned to one side. I don't remember which way I bent them but it should be easy to figure out. You'll need to bend them in the same direction to reinstall the booster.
I don't think you're not actually bending the studs, it bends where the studs are attached to the booster IIRC.