You most likely could do this without any further internal support. I read through and saw Rogers build a while back, yours would be identical. For your truck if you do it, I'd remove the seat, steering column, windshield, doors and floor mat, just so they are out of the way and won't get damaged/dirty. Not too hard or too much work to do that. Cover the dash with a couple welding blankets to protect it. Then go to town on it!. It's definitely doable. Just take your time, try not to get frustrated.
Only reason why I completely replaced both panels is I had pin holes going all the way around the roof along the drip rails.
