Not sure if the installation instructions with the Powerflex bushes have been updated, but looking at a recent set it says to install the larger lip of the rear bush against the radiussed edge of the wishbone.
This means that one bush has the larger lip on the top side, the other has it on the bottom as that is how the cast wishbones have the radius.
Just that any pictures I've seen of poly'd LCR wishbones have them both done the same way.
Just use a 5mm drill bit and drill through the aluminium casing of the bush, at worst you'll make a tiny scuff mark in the cast iron of the arm. You use the drill to do what the hacksaw does when you're cutting it. Then the entire thing just knocks out with two taps of a hammer.
No need for fire, hacksaws, or spending hours taking them out