...usually requiring a rubber mallet to hammer them into place!
Which should be done
very carefully... the hammering that is...
I rather also lube the 5 pins with a slight smear of Moly-paste, and then squeeze & wiggle the thing in place by hand only...
There is a risk of pushing the new aluminium bushings out the new rubbers when "hammering" the splines into place...
Further need those cush-dampers to be
fully seated prior installing the holding plate.
Some use rubbing alcohol, some silicone spray, I powder them with talcum, insert them in the pockets inside the rim, to then use a 3/8" ratchet extension and a plastic mallet to "hammer" them fully into the wheel (only apply force on the rubber, never on the bushings).
Apply a small drop of medium Loctite on the threads of the 5 bolts fixing the holding plate, do not exceed the rated 20Nm on them...
Check the (3) O-rings, do the usual lubing procedures....