bloody hard work without a hydraulic/pneumatic tyre press..
in my youth i worked as a tyre fitter in treadex tyre & exhaust, Banbury...
basically, the chances are that without the right tools, you will knacker the rim, or the tyre, or both,
especially on low aspect ration tyres like we use on Omegas.... the whole point of the low aspect is to stiffen the sidewall, which makes the tyre much harder to remove or fit....
(and coincidentally improves handling

)
never mind the whole issue of balancing..... spinning the thing fast enough and measuring the wobble accurately enough is not trivial....
on old school 80% aspect ratio tyres, it's possible , indeed, even relatively easy to do it by hand using what amount to big tyre levers....
it gets harder the lower the ratio, by the time you get to 60% you can forget ever doing it by hand..... and as for our 45% tyres on miggys... not a chance, ever....