Removal can be done with hear or mechanical methods. Heat is faster but has more risk. Sawing then filing is slow but easier to control the goings on.

Plan on new bosses. Take care as to location and placement as different canits like somewhat different boss to boss widths. Also the spring holes really want to be symmetrically positioned so the two side will be able to be centered. Use brass/bronze if you're brazing them on, silver is too touchy to large gaps and learning this the hard way isn't a good choice with one's brakes.

This isn't the project that I would suggest for a newbie who has no brazing or metal fab experience. Andy