[monocoque]

I've been removing floor bolts the most difficult way possible. I've been using an angle grinder to grind off the heads. This creates a lot of smoke and during the process requires wearing safety glasses and a particle mask. Usually my eyes are watering and I'm holding my breath to avoid inhaling the smoke created by the grinder contacting the wooden floor. A friend watching this process suggested that I get a 1/2 drill, one with a lot of torque, and back these phillips head self tapping bolts out mechanically. Somewhere I read that these floor bolts are bent back under the frame but I have found most of them unbent. I've tried to back these out by hand but the majority of them are frozen tight. Is there an easier way?