How to Troubleshoot & Replace Bosch AP3799123 / 00424717 Dishwasher Upper Rack Roller Set

No problem 

I rotated to the outside the plastic retaining clips on the right and left arms holding the rack, slid the rack out and placed it on the kitchen counter. I used a pair of needle nose pliers to pop the wheel axle off the rack. I pressed the new wheel onto it's axle and then pressed this axle assembly onto the rack axle and rotated the assembly retaining clip to lock onto the rack. I then slid the rack onto the two rails all the way back and rotated the plastic retaining clips at the end of the rails back into their lock position. It's a very simple procedure taking less than 5 minutes. 

Replaced them. 

Installed new roller