Flywheel side crank bearing advice

PX 125 disc.Just wondering how far in do you position the innner race onto the shaft when fitting is it right up to the crank web or is it a set gap say 0.5 mm.Also any advice on removing the old inner race off the crank .Just did the same job on my ets and used a mini grinder and ground through the bearing till very thin and managed to drive off with a little chisel but found this method very risky as didnt want to damage the crank. 

Hi, a bearing extractor would be a good tool to have for the job. There is a gap of about .5mm as you’ve mentioned.

Youve probably done it now but seen you hadnt had a reply.

If not go on www.beedspeed.com forum it seems a good forum and all posts seem to get answered.

I would not ask on the Beedspeed forum, they all seem a bit green around the gills.  Best is Scooterboyworld, lots of experienced rally goers and home build scooter enthusiasts.