These vintage lenses are very high quality and capable of producing amazing images. One thing to look out for - carefully inspect the lens for defects and repairs it may need before you start the conversion. Full frame Canon users - if the rear lens element extends past the M42 / EF mounting into the mirror box by .040 of an inch or more it will interfere with the mirror movement. This translates to not being able to focus beyond about 15 ft. on the full frame Canon cameras.
Every lens type is different. This video is specific to the Rokkor PF lenses. However, the concept can be applied to most lenses that have a screwed on mounting. This procedure with not work with the Rokkor PG lenses. They are a little more complicated to convert.
All the photos used in the video were taken with a Minolta 58mm f1.4 PF lens, except the one shot of the camera. The video runs for about 12 min but it will take a good part of a day to do a conversion. More advice, don't take the lens apart any further than necessary. Its really easy to turn a perfectly good lens into a useless piece of junk.