It is easy. RCBS sells a stuck case removal kit for a few bucks. But if you are at all mechanically inclined you can put one together your self. Go to a hardware store and get the following stuff;
1. tap drill for a 1/4-20 - I think it is a #7 or a 15/64 drill. and a 1/4-20 tap. ( if your metric only in your area get a 6mm tap drill and coarse thread tap. ) Also get a bolt 1/4-20 bolt that is about an inch or less long. Also, Get several large washers that are over 1" outside diameter and ID less than the bolt head. Depending how you are set up for tools, you may need a drill motor, tap handle, and wrench for the bolt also.
2. At home remove the die from the press and loosen the neck expander and get it up out of the way. Screw the die in upside down in the press but leave it about 1/4 inch from coming aobve the top of the press.
3. Drill out the primer pocket with the tap drill and run the tap in.
4. Place washer(s) over the head of the press. place some lube on the face of the washers(drop of gun oil). Run the 1/4 inch bolt in so as to extract the case against the thread of the bolt. Your wrench twisting the bolt will do all the work.
The case will be destroyed but with a damaged rim it is of no use anyway. Check your practice on lubing the case before sizing to prevent recurrence. I use imperial sizing wax and haven't had a stuck case in years.