The head unit faceplate is just held on by clips. Have you tried pushing the faceplate towards the dash? When you take it off, you just pull the faceplate towards you (towards teh back of the cab). Are you the original owner or did you buy the truck used? It could be that if the truck was used, maybe the old owner took the stereo faceplate off and lost the metal clips.
As far as the ac knobs, is the knob itself just broken (cracked) or does it not change the settings. If the knob itself is just cracked or missing, you can buy the part (the part number is 27560U). They run about $15 each
Here is a link to the part
http://www.courtesyparts.com/kb_search_result.php?keywords=[27560U]+\%28a60&cPath=1244_1245_1281_1297
If they knob isnt changing the settings of the air unit, the inside of the knob area may be broken which will require more work. You will either have to fix it yourself or buy a whole new ac panel. There is a thread where someone came up with a homemade fix. I'll try to find the link.