Volvo wear pads replacement drive axle suspenssion

Any tips on how to install this
Z spring wear plates/pads,plz?
I noticed my pads are worn out, thet have less than half thickness of new ones and gets bumpy. I stopped at Volvo today , but they didn't have time to do it, soo i purchased the parts 14$ each and thinking to hammer them in, shouldn't be very difficult but never done this . Should the thicker side be in front ? I can't find any info on internet, any tips plz.

 

Thx Snailexpress,
so, the roller need to come out first, i'm going to try. I owe you a pack of beer!

 

KB, 1,288,000 ,
i put new reman in september last year, the wear pads have about 200,000 miles.

 

Trucker, I've been told years ago to check them and replace before the spring touches the hanger. I used to run Transcanada Hwy on rough compact frozen snow , they wont last a winter, but the cold perhaps makes this plastic more brittle . When this things are worn out are more damaging than bad shocks, ,spring starts banging denting the hangar, i got snapped springs, leaking hub seal, leaning and rough ride .

Here how my pads are looking now, not really bad but not far from done, I'll replace when I get home.