Are the splines on the non-drive side also totally destroyed? And what kind of BB is it, Shimano or something else? If the non-drive splines are still in good shape and you have the proper spline tool to fit them, a pneumatic impact wrench (or a 2' long breaker bar) should make short work of getting it out if it's also seized up, just make sure you have the right spline tool and the splines are fully engaged or you will tear them out too.
If it's a Shimano or other cartridge BB, once the non-drive side cup it out of the way you can tap the main cartridge (bearings and spindle assembly) out of the drive side cup and then use a hacksaw blade to cut the remaining cup out.
If you don't have a work stand to hold the bike, get someone to hold it steady for you. You'll never get the spline tool to stay seated if you're trying to balance the bike against a wall while putting a lot of pressure on it, the bike will just move around and you'll end up stripping out the existing splines (if any are left).
If it's a Shimano or other cartridge BB, once the non-drive side cup it out of the way you can tap the main cartridge (bearings and spindle assembly) out of the drive side cup and then use a hacksaw blade to cut the remaining cup out.
If you don't have a work stand to hold the bike, get someone to hold it steady for you. You'll never get the spline tool to stay seated if you're trying to balance the bike against a wall while putting a lot of pressure on it, the bike will just move around and you'll end up stripping out the existing splines (if any are left).