hydraulic to mechanical brake light switch

I have a 64 1/2 . For the umpteenth time the brake lights quit working.
The hydraulic switch seems to last less than a year. I read somewhere
that it isnt difficult to convert to mechanical switch from a later
year. Anyone have a link to the relevant part and whats required ? Does
the pedal mount have to come off to be drilled or anything like that ?

Thanks

G