Is there a trick to keeping the blades from turning while trying to loosen them? While looking under the mower from the front, I attempt to turn the bolt counter clockwise to loosen the bolt. Naturally, the blade simply spins as I turn the bolt, and I get no where. Is there a trick to this, or do you just try to wedge something in and go for it? Thanks, TMR BTW, I'm dealing with a Metro 48"