Well, after a lot of swearing, a candle lighter, two screwdrivers; one that was already bent at the tip thanks to a paint can haha, a wrench, and my good old friend of mine, we managed to get the pulley off of the axle. Hooray! Now just need to epoxy on more HDPE to it, then go from there.

But it does mean we're back on the right track, somewhat.

Also, thanks Nat for the idea with the lighter, worked a treat on wearing the glue out, and the heat expansion too.