80 Series headlight switch

Something happened to my main headlight relay and in turn my headlight switch burned out. There is a heat damage to plastic casing. I have new one on order and luckily 80 series combination switch comes apart so you can change individual switches rather than forking out 500.00 or so for new combination swith. I took the steering wheel off and headlight swich can now be separated. There is a plastic cup/cover on the swich end and once taken off one can see plastic retainer.
Here is a question, i never done one of these before so do i have to destroy this retainer in order to get internals out or is there another way? Generaly, how do you replace this headlight / tail light switch ? Any info is appreciated.