If they're like the '29-'32 seats, they're very easy to remove: Simply lift up vertically on the front edge, then slide forward. They're simply sitting on a wooden base, held in place by a 1" wide metal strip around the wooden base. There are no screws, bolts or anything to remove. You just lift up on the front of the bottom cushion, get it clear of the metal strip and then slide it forward about six inches to clear the rear cushion. Then you can tilt it and lift it out fo the car.
Caveat: If your '33 is a coach (a two-door sedan), the bucket seats have to be unbolted where they are fastened to the floor. The description above is for a sedan only.
Hope that helps.
All the Best, Chip