broken sliding headliner...DIY?

My black sliding headliner is now broken. I must have snapped a tab or something because now it won't slide on its track. Is this a relatively simple fix or something that should be handled by a professional? Does it need special tools? All day affair? If it is indeed a DIY, could someone give a general step by step or link to a guide? Thanks in advance.

Also, where is the best place to get the parts? I'm assuming dealer only.http://forums1.roadfly.com/preferenc....php?img=23351

Google of E46 sunroof diy yields (among others)
http://www.jumboprawn.net/jesse/projs/bmw_e46_sunroof/

already (under warranty, thank goodness) and it is really tight right now, may have to do this DIY just to lube it up, thanks.

Seems pretty good, but I have not tried it myself yet.