To unfit the ring, as described above just need to be heated a bit with flamme (no need to be red ! just heated a bit...200°C is almost sufficient...) and hammer it out.
about the tolerances....
i do it a number of times.
this is veryt tigth !
when its build it is in mm, there is a 0.20 to 0.25 mm of tighten, its very high... i mean that the ring diameter is smaller than the flywheel diameter.
when you heat her she grows up, then fit, and when it cold down it release and hold on.
in most common of time very tigthen is 0.15 to 0.18 mm for a such size, but for this it appears very large...also fitted in a alloy flywheel we are somewhere afraid by a collapse somewhere.
its a tighten tolerance with the 0 on the flywheel.
the flywheel is 257 h6:
257mm +0
............-0.03
and the surface finish must be:
Ra 0.6 to 0.8
(with this, and above you dont need to put screws or thing else to tigthen him in place)
sorry guy i dont know more about us standarts...
old ring when dismantled had
257mm -0.020
............-0.025
i check this of 3 dismantled rings..so it must be correct.
if you did a complete custom thing, you can reverse the ring to get the unused tooth engagement side.
where is was working on past, they had a lot of machining capacity, i measure it with a 3axis mesure machine from mitituyo, i had a do a such of thing with this it was great.
it is always great...when you can do it free, now
i had to pay serious prices
also if you fit it in a alloy flywheel...it is possible that you can never pull it in the future, because of alloy flywhell grow up faster than ring when you heat them.
if you try you can damage the both...(perhaps ! but probable...)
, but how does one go about removing a ring gear, and once it is off how do you put it back on? 
