How can I remove a stuck circuit breaker from the panel?
First item of order is to identify this breaker panel and find out if there is a national recognized fire hazard danger from the make and model breaker panel you have installed. 

Square D, Zinsco/Sylvania and Federal Pacific had failure modes where this happens.

Stop, call a qualified electrician and have them inspect the panel. The bus bar contacts are burned and the circuit breaker may have partially welded itself to the contact. At this point, the meter needs to be pulled if you don't have a 200A main breaker that shuts the panel off. Any force trying to remove the breakers that breaks the insulators holding the bus in place will put you in a potentially deadly or high property damage situation if you do not cut the power before proceeding.

In the case of Sylvania/Zinsco, the aluminum bus bar may burn through from the arcing. The only over-current protection you have will be the transformer fuse which will blow only after the bus bar has completely consumed itself in an arc flash fire if it contacts the grounded panel housing.