a few things to ponder when replacing UJs and bearings.
Firsts of all you are replacing the bearings. There is no need to get them out intact. They have no pre-loved value whatsoever.
That means the VCU bearings are best removed by cutting with an angle grinder.
And in the past on other cars I have literally smashed the brittle case hardened outer shell of UJs with a cold chisel.
to get a UJ back into the yokes consists in taking the outer shells off the spider completely being careful to retain all your balls. Especially if newly wed. Then carefully press one shell into one of the yokes using a vice and ultimately a socket to push it just below the yoke surface so you can refit the circlip.
Then fit the spider to that and using the vice and socket push the other shell in.
Then repeat for the other yoke.
You CAN use this way to get the old bearings out but not the whole way in my experience. if you can't then grab the bearing outer shell in a vice to remove it that way, which buggers it anyway, the only recourse is to smash it.
As far as VCU bearings go, just carve the buggers off with a grinder and then spilt them.
As Hippos says the difficult part is splitting the centre yokes from the VCU, and that takes a lot of pressure and penetrating oil. Heat is not a good idea when you have oil filled bearings and rubber seals nearby.
A videos I saw used the centre bolts into the VCU together with a spacer to use the unscrew thrust of the bolt that holds em together to force them apart. Essentially jam something between the bolt head and the UJ spider, and continue unscrewing the bolt - as it comes out it forces the yoke off the shaft.
This will not be as easy as it sounds. genle heat on the shaft and yoke followed by penetrating oil to cool it may help some.
So too will massively hard blows along the shaft axis on the yoke itself. Again use a spacer to avoid damaging the yoke between the hammer and the yoke...
I think I would say that in the end, although brute force on a puller is the least damaging way to split components apart, the actual force required is massive and often harder to apply that some well placed thwacks with a hammer and cold chisel.
So the general technique should be first to try as much heat as the components will safely stand, and spray penetrating oil on the things too, then try the puller methods first, and the, preferably with tension on the puller, tap and than bang away at the component.
And never be afraid to destroy what you are going to replace, anyway.