[Lemuzz]

Nope - I was the idiot that got it stuck! Can’t blame anyone else! It’s not ceased in there through age or dirt - I was just too dumb to read how a collet and nut worked when you changed bits!
Do you reckon these freeze sprays are worth a go?
Debating stinking the whole router in a freezer as well - then heating the bit in the morning!

when using heat (or cold as that is another form of heat) the secret is to only heat the part that needs to be expanded or using Rapid Freeze to shrink the part Because you cant heat the shaft without heating the collet you will have to use another method. I suggest sacrificing the bit by gripping it with vicegrips and hitting the vicegrips with a hammer. I had a Bosh router which had a flange on the collet. As the nut was unthreaded it pulled the collet out from its recess. I don't know why all others don't use this.