Another way to remove the T nuts is to screw in a long bolt from the topside of the playfield so it is out the bottom of the T nut, then gently tap it from above until it is free then simply unscrew the T nut and remove the bolt. Just take care of the topside of the playfield when tapping it out.
Cheers
GP
That's the method I use.
Metal guides - "tap" them with a small hammer. Don't bash them hard as they can take a chunk of playfield on the way out. Make sure all the other nuts are removed from the guide. Wiggle it to loosen it from the top of the playfield.