One for you engineering types out there. One of my far too many projects is to get a ride on mower up running from 2 scrap ones. I now have a chassis that I can drive around but it wont cut much grass as the the bearings in the cutting deck are shot. I have, to my surprise, managed to sort out replacements despite them being a mix of metric and imperial in the one bearing? There are 2 but they sit in an aluminium housing that bolts to the deck. I thought about drifting them out but I remember something about the assembly needed to be heated or cooled to allow the bearings to removed more easily but I cant work out which route to take. Which do I do and why please, before my head explodes with the thought process behind it?