I'm 70. I lift 5 lb weights tri-weekly to make sure I can bring home the groceries or turn the bike over to fix a flat. Watch Margaret Richards on Body Electric on PBS if you don't know how. Or another pilates source. I do curls, over head, extensions to quarter & side, 30 reps when up to it. No jerky movements for the aged. I do it in the easy chair as I watch TV, no time lost. I also do toe touches with the weights to keep up back muscles.
I don't have a display. If you do you'll have to turn it down or remove it to keep from damaging it with the bike upside down. I flip the bike from side onto handgrips & seat. Keeps the fenders & hangers from getting bent.
If a hub motor, you have to unplug it or remove enough tie-wraps to get a couple of feet of wire slack to get the wheel away from the frame to change the tube.
I never patch tubes, I change them.
Look at the chain as you're pulling axle up & out, you'll have to stick the axle back in there the same position before putting the axle back in the slot. It goes in the loop, then the hook the chain over the same sprocket it was in when you pulled it out, then push down axle into slot. I use open end axle wrench to handle the chain to keep my fingers clean.
I'm not strong enough to preload the derailleur takeup, I have to use channel-lock pliers, that I carry with the other tire tools.
Takes me under an hour on the hub motor end, about 40 min on the regular wheel end. that includes unloading and untieing the panniers to reach the axle, then reloading & tieing back on. I use binder twine, big tie wraps would pop loose under the weight of my groceries. I use the slip knot on one end then the half hitch against it to secure the loop.