I don't have anything to add for the specific requirement of removing ones harness, the live-demonstration/mirroring recommendations in other answers should do just fine. I want to address a slightly more general point:
[...] without touching them
It should become blatantly clear from what follows (and shouldn't be a debatable point anyway), but to be safe: If anyone does not want to get touched, you don't.
However invading the personal space of your climbing partner is not optional. Before climbing you always do a proper partner check and that involves checking manually that biners are locked, harness sits tight, ... That's even true for top-roping. If we are talking about leading (high first bolts) or bouldering, the need for touch becomes even more blatant due to spotting. If the climbers hip gets above your shoulder height, the point of initial contact in case of a fall is the hip. Is this potentially awkward? Sure. Is it better than falling directly on your tailbone from ~2m? I think so.
The important point is to explain early and clearly why and in what situation it is necessary to touch or get into the others personal space. It needs to be abundantly clear that it is a safety necessity. Then ask individually when the situation comes up. The consequence is, that if someone legitimately feels uncomfortable about it, you either need to get someone else to do the partner check, or in case of spotting, you just can't do the climb. In general if you can't bear your belayer to touch your harness and hold your behind/back/... in case of a fall while spotting, you might want to rethink whether you want those persons to belay you - they do hold your live in their hands when doing that.