Ya got a push the clutch inside the drum further.
Make a recheck if all bolts ben removed or a broken bolt
If it's really rusted up and the clutch pack swelled it isn't going to happen.
You really need to try to break the brake drum loose from the flange that holds it in place. On my 14A I used a short flat bar with an 8 pound sledge hammer to move it. You may need to move the tractor forward and back to break it open on all sides.