On my 04 Three of the Four screws per trim piece was rusted to death, i basically pulled them out. I replaced with new screws as JD said. Some of the carpet was through the screws but it is mainly pressure that holds it in from being screwed down. Trying to tuck the carpet back in would be a pain.
If memory serves me right this is an easy way to get it apart since I think you said you want to remove the headliner too.
Pull the door trim pieces your talking about now.
Pull the side bezels near your feet, it has stupid trim panel pieces and snaps in.
Pull the A/B Pillars (remove grab handles, I think my 04 had two 8mm bolts). then pull out Pillars.
Remove seat belt by unscrewing Torx bolt at floor and bolt at the top.
Remove rear trim panel, then you can remove the rear panel below the window.
Remove seats by unscrewing the 18mm (I think) bolts that hold it to the floor, plus the two that hold the middle passenger seat belt into place. Remove electrical connectors from under seat.
Remove cup holder bezel
I'm 99% sure you have to remove the top cover for the shifter if you have a Manual, can't remember what its technical name is but you'll see it when you remove the bezel. It had some sheet metal screws that held it down (I replaced with much longer ones once I put carpet in, it wouldn't squash down enough with the stubby screws they had on there. I wasted 1 hour, Just to save you time if they don't screw back down easily get longer ones, lol)
If you have never removed the seats before go under the truck and spray all four bolts per seat and the two that hold the middle seat belt with Penetrating oil several times. Mine where not to badly rusted, but the two with the seat belt I had to drill out....
Once you have it all out you can remove the head liner, I think it has those trim panel connectors and you have to remove the dome light. I haven't done it yet. You said you had an OHC so I'm sure you know 80%+ of everything I said, but you have your big project coming up so I just listed everything you'll need to know in one go.