Do they come off by just unscrewing them?


I misunderstood the definition of retrofit, i thought the retrofittings screwed ontop of the existing valves, but infact you have to remove the existing valves.

My question is how do i do that (remove the existing valve)

 

the schrader valve will twist out just like a tire valve. with a valve tool. or a pair of skinny needle nose if you are lucky. the tool is the right way