Im not saying the bearing tool is mandatory...

Here's ways I've removed them in the past.

1) In the oven, 150c.. ( It takes a while to warm up and it's awkward to handle as you have to grab it with oven gloves - This method always worked as the entire block is hot)

2) Find a teflon insert to the crankcase to use as a holder, I have a small screwdriver handle that works. Insert the handle and use the stove top gas to heat up the crank around the bearings. Have a chopping board handy and when the oils start smoking, you're at around 150c. A good hard tap on the chopping board and it comes out.

3) As above in step 2 with a butane torch, for remote emergencies.

4) Find someone with a bearing puller!

And..

Yes, I put new bearings in the fridge/freezer to cool before install

Yes, you can try freezing your bearing with butane or propellant to get it out, but if it didnt come out with heat, it wont be likely to come out with freeze etc.