IMHO, most maintenance is really easy, and some is pretty hard because it needs special tools or knowledge/techniques.
So I would not remove the prop (a 2 man job anyway) or do anything on the retractable gear.
However, it's perhaps true that the biggest cost savings come not from doing pretty coarse machinery maintenance (like changing the vacuum pump, skinning your fingers in the process) but from doing avionics or electrical work. This work is traditionally very expensive and generally a big hassle, because avionics shops most of all hate doing small jobs, like replacing a single instrument, and don't even return calls if remotely busy unless you are a big regular spender. Also there are not many of them around, especially if you are looking for one with some level of competence.
The savings which can be had from DIY avionics/electrical work are massive. I've just had a vacuum driven AI pack up (a complicated one with a flight director and analog outputs for pitch/roll). This costs an eye watering $11k (mail order from the USA) but would be billed at something like £8k if bought in the UK. I ordered an exchange refurb one (basically rebuilt to new standard) for $3k, popped it in, got it signed off, and off I go. Otherwise I would have had to hassle a load of avionics shops to see if one can do it, fly there (VFR only of course), and spend a whole day on this job. And not many are keen on installing customer issued kit.
Most avionics shops seem really busy doing £10k refits these days.
Whereas any maintenance firm can change a vacuum pump, or brake pads.