Unless you intend to convert the action to double action-only, all you have to do is cut the spur off, round and de-burr the cut area, then fire 100 rounds of ammo to test for reliable ignition.
Many people doing "hammerless" jobs convert to DA-only to prevent any chance of cocking the hammer and then not being able to uncock it.
To do a DA-only conversion, you disassemble the action and carefully grind away the hammer's single action area so it can't be cocked.
The single MOST important part of a spur cut down, is the reliability test.
DON'T cheat on it.
