I had a machinist pal make me a tool specific to Porsche sealed RWB that is something like this set
https://www.amazon.com/Orion-Motor-T...969059348&th=1
Using this type of tool makes this job so easy. I typically clean the inside of the bearing socket in the arm with some emory paper to get any high spots and corrosion off. Once clean, I smear a thin coat of Castrol Optimol (lithium) paste on the inside of the arm race.This keeps the bearing from binding and going in crooked. Heat it with a MAP gas torch and use the tool to pull it back in. Note the first few mm are the most important to make sure the bearing is going in straight. If it gets crooked it will peel some of the aluminum metal and may get wedged when the bearing bottoms out and you won't be able to get the snap ring or bearing cover on all the way.
Another tip is to take the dust deal off the sealed bearing and make sure it is greased properly with a good grease. There have many instances of poorly greased bearings failing prematurely due to this. Easy to do
I use Mobilth SHC220 grease for the race cars as recommended to me by a Porsche pro race team mechanic and supplier.