Okay, but what's the problem with loosening the driveshaft nut to create some space?
I think: it's better to be more careful and take things apart further to minimize the risk of damaging something (like the expensive ABS sensor).
You could also try the "Russian method": hammer a suitable, thick drift between the loosened nut and the top of the ball joint; this will press the joint downwards and outwards. However, I won't do it that way. If the outer ball joint fails sometime in the future, I'll just have to pay for it. No.
And lowering the jack also helps to ensure that you strike the old rubber bushing squarely with the chisel, rather than at an angle.
However, I think the idea of drilling a hole through the old hammer is practical; it doesn't matter if it's a neatly welded and drilled part or something else that's being pressed through.
What's much more important is the correctly sized spacer that presses against the rubber bushing from the outside, rather than just pressing against the rubber from the inside.
Gruß, der Teileklaus
Touran 2017 DFG SCR 2,0, 150 PS Schalt
Fiat 500, Einkaufswagen
R1240R BIG Bore Tuningkuh, 142 NM
What is much more important is the correctly sized washer that presses against the rubber bushing from the outside when it is being installed, rather than just against the rubber from the inside.