You have to more or less butcher the two inner bearings to get them out
Completely disagree with you on that. Just buy a threaded rod (~8mm), nut, some washers and a suitably sized socket and the bearings in the freehub are p1ss easy to remove. I use a ISIS BB non-driveside ring instead of a socket – perfect size.
I bet you can even use the main hub axle as a drift as it'll be perfectly sized to remove the bearings without trashing them.
The easiest way to reassemble is to put the two inner freehub bearings back in using a vice or G-clamp (gently!), then lightly tap the outer bearing into place and either use the threaded rod/washers or just put the whole hub back together onto the wheel and use the qr to slowly press everything back together.
Remember to put a light smear of grease around the bearings when you put them back in, otherwise they'll seize in place after a few months of wet riding.
If the bearings are well and truly seized then putting an old cassette on often makes it easier as there's more to grip/brace the hub with.