I can't speak for your car specifically, but I had to drop the headliners in LOTS of cars to do 2 way radio installs for my old job.
Usually, you do it by removing the sunvisors, the grab handles, the center light, and the pinch-windlass(the plastic/rubber liner around the door openings) and often you also have to un-attach the covers over the pillars that hold up the roof. With a sunroof, you may have to remove a windlass around the sunroof opening and whatever may be attached below the headliner itself.
Essentially, it should just be a large shaped piece of cardboard with headliner material glued on. You may or may not be able to get the headliner out of the cab once you get it dropped.
Patience is a must, you'll probably need a selection of torx head screwdrivers; the plastic pillar covers usually seem to be held on with metal clips that push into slots in the pillar steel. Ie: you pull the pillar plastic VERY CAREFULLY and if the "gods" aren't angry with you, the clip should "pop" out of its slot OR it MAY come off the plastic - either way, be very careful when pulling them. Unless you got uber lucky and they attach with screws or one of the other types of plastic attachments used for those things (some you have to pull an insert out, etc.).
Essentially, you need to be curious and careful.
You know, like entering a dungeon in an old school rpg. Take a step, examine for traps. Take another step. Examine for traps. ;)