My driver's seat belt will not retract, and unfortunately it's not stuck at a long enough length to buckle me in.

Has anyone else had to get into the belt mechanism for any work? I'm not too keen on removing interior trim, it never seems to go back as tight when you re-assemble.

Any tips/tricks would be appreciated.

 

Do you mean the seatbelt is extended out and won't wind back up again?

If so, is it possible that the belt is simply friction-stuck in the height-adjustable plastic part at the top of the central/B pillar? It is quite common for fluff and general dirt to build up where the belt wipes over the plastic part and eventually that jams the belt preventing it from retracting. Normally you will notice the belt retracting slowly for some time prior to a complete jam. Worth checking just in case. They are easily cleaned without disassembly by inserting a triangle piece of card into the slot above and below the belt and rapidly pulling it in and out to displace the dirt, then wipe the belt clean. (The dirt is normally the hard/compacted kind build-up get on the feet of computer mice, so it needs abrasive removal.)

If that's not it and the failure is at the actual retractor/spool then you can easily remove the trim by just pulling it off towards the middle of the car:
1) Remove the door weather seals both sides along the seam with the pillar trim. It just pulls off.
2) Remove the base of the trim and work upwards. You can see the clips from the edges with the weather seals removed.

That will expose the belt so you can check that, and the spool is inside the pillar towards the bottom held in place with a bolt and locating tabs.

Note that some vehicles have the explosive charge for the seatbelt tensioner at the spool end rather than the belt clip end. If you have a yellow cable connector on your spool then be careful. If you remove it then disconnect the battery negative terminal for 2 mins first.

When reassembling you can use a blunt knife to pull the edge of the weather seal over the fabric/leather on the trim. Fingers work too, but it is much easier with a blunt blade.

I've taken the pillar trims off a couple of times on mine and not had an issue with the clips breaking or misalignment on reassembly.

 

Yes, extended out and won't wind back up. My wife has been driving it the past few days, and she said it happened a few days ago, but eventually retracted. Happened again yesterday, and so far it hasn't wound back up yet.

Thanks for the quick tips! I'll dive into into it during the Thanksgiving holiday break.