I did the rear shocks a couple of weeks ago on my 300E, which has a similar setup to the 190's, I think. My write-up is here:

http://www.peachparts.com/shopforum/showthread.php?t=119993&highlight=rear+shocks+300e

It's pretty straightforward once you get the hang of it. I didn't need any special tools for the shocks, don't know about the thrust arms (but it doesn't sound like it).