Lots of people do the "MARS" mod to there ham radio's. why would it be such an issue.
whats that famous saying? those without sin may cast the first stone.
I dont see what the big problem is.
Back to the original question, sorry mate you may not find the right answer here. (some people may be a bit reluctant to give you the information because they feel it is wrong or immoral for some reason) but my suggestion would be dont give up "google'ing" it. Infact if you type in "kenwood ts 480 MARS mod" you WILL find it about the 3rd in the list will be very helpful
Mod away. experimenting is what Ham radio is all about.