I've done that. I've even taken apart computers that used CORE Memory. The Little Magnetic Donuts.
Nearly all 35mm cameras have a wind lock to prevent the film being wound twice. But they vary considerably in where they are and how they work. Often they are under the base plate but they may not be. Sometimes they are part of the advance mechanism under the top plate. They can be difficult to get at or may be easy. The lock itself rarely causes problems - it's always something else that causes the jam, releasing the wind lock is just a possible solution. Most 35mm SLRs have a sequence of events that happen whenever they are released (press shutter release - mirror up - shutter open - shutter close - mirror down - wind lock released), if any part of the sequence fails to complete, the camera freezes and, because releasing the wind lock is the last part of the sequence, it becomes locked. Often just recocking the camera will clear the initial problem but you need to manually release the wind lock first to do that.
