Hi Nigel, I did a refurb on an OS 46 AX last summer and found that once everything was stripped other than the bearings, a quick stint in the oven at 160 expanded the case a little so you can tap it out gently with a dowel.
Whole process took less than 20 mins, including explaining to the wife that it would not ruin the Sunday roast!
Same process for fitting new ones after in reverse order.
Hope this helps.