how did you get on?.... i watched a good clip on youtube the other day btw made by GOWESTY about servicing the sliding door.
https://www.youtube.com/watch?v=M5UrduOCJws" onclick="window.open(this.href);return false; (2 parts)
Its a good vid to follow for the process and is possible to simplify things as required.. ie if you whip bearings off and they are ok then simple clean with brake cleaner and a re grease will do the job, or a simple degrease, wirebrush and re grease will make a big difference to the runner etc..
Only thing i would do extra is not to rely on the wittness marks made by the bolts but to draw around them with a thin marker or scratch with a scribe to align the door exactly.. or take 5 mins and a straight edge to check the alignment of the door and re- adjust on assembly..
regards