Thanks for reaching out to us! Look toward the side back end of the roller housing. You will see that there is a slotted adjustment screw. When you turn this screw, it should bring the wheel to the correct height you need.
Awesome, I'm glad to hear that it worked out for you! We appreciate your analysis, too. I'm sure this will help other customers in the future who are in a similar situation.
What you need to do is to turn the adjustment screw counterclockwise (to the left) to have the wheel come down. When you turn it clockwise (to the right) it will go back up and clip in place. I recommend you hold the door up when adjusting the screw to take the weight off of it.
I apologize for the misunderstanding on the Norco roller. You are correct to slide something like a thin "blade" up the side of the housing to bring down the wheel. Also, it might be possible to remove the roller from the door by pushing up a small thin blade in the seam at the back of the roller to release the nylon clip. Apologies again!
