There appears to be some confusion here between "changing a tyre", "repairing a puncture" and "complete and thorough dis-assembly, inspection and overhaul as necessary".
What I had in mind in my original post was this:
You're at an airfield with no maintenance facility, a long way from home.
Your tyre goes flat.
You have either a spare tube, a puncture repair kit, or a tin of tyre weld.
You also have access to any tools you need.
Your regular maintenance organisation can't come out to you for a week because they're too busy and it's too far.
You're very experienced in things mechanical.
Do you get the train home and wait for the licenced engineer to find time to get to the aircraft, or do you effect a repair and fly home or to an airfield where maintenance is available?
I know what I'd do!