high beam switch
Hi
If you unscrew the 2 screws that hold the switch to the bars (from underneath) and gently open the 2 parts of the switch, you can remove the whole thing while still connected. I would say WD40 is likely to sort the problem, but if you are sure the switch is dead, I have some damaged clusters with a good switch I could send you. What year is the bike? Does it have always-on lights? Is the horn above or below the indicators? New switch would need to be soldered in.
On the relay, I think there are 3 the same, so you could swap one out and see if that changes anything.