Can you take a pic of where you mean mate ?
Okay, here's the full monty...
My door starting scraping today so it forced me to do this job...
This is the part you need to remove to get the lower roller out.
1. First you need to chock the door so it won't hit the side of the van when you undo the lower roller bracket bolts. Open the sliding door fully until it latches at the end of its travel:
A length of 2x3 is enough to take the weight of the door without marking the bodywork.
2. Undo the two torx bolts on the lower bracket noting the position in the slots for later:
3. Move the roller away from the latch mechanism - it's hard without the door attached, put some effort in! Undo the two bolts holding the roller latch mechanism inside the lower roller guide:
4. Now drop out the mechanism and roll the roller back and it should fall out into your hand. Mine was showing why it was scraping:
5. Reverse the steps to refit the door. I needed my wife's help to take the weight of the door when re-attaching the bolts on the bracket, as they needed to be at the furthest point in their slots.