Both of my T-100 trucks had fogged up headlights. I got them clear without a whole lot of fuss with some simple tools and little effort. You can do it without power tools and use a sander block and a microfiber towel...you'll be proud of yer handy work but you'll be pretty tired and maybe some blisters on yer hands/fingers. 
I have some wet/dry sandpaper (1000, 1500, and 2000 grit) which I attached to my palm sander. The key is to use some soapy water in a spray bottle to keep the sander from melting the plastic (which isn't good) and making a big mess. Keep the sandpaper wet with solution as you work it gently over the headlight. You might want to mask off the grill with some cereal box cardboard or tape depending on how crazy you git with the sander. The headlight should be pretty smooth and almost clear. I have some Plast-X plastic polish and a Mother's PowerBall on my power drill. A little polish on the ball and start off at a slow speed. Eventually build up the speed and work it over the headlight. In no time at all, yer headlight should be nice and smooth and almost like new again.
You'll git more light on the road to see with! Just touch up the headlights once a month with some plastic polish and a microfiber towel and you'll be able git the max light out of yer headlights everytime.
I have some wet/dry sandpaper (1000, 1500, and 2000 grit) which I attached to my palm sander. The key is to use some soapy water in a spray bottle to keep the sander from melting the plastic (which isn't good) and making a big mess. Keep the sandpaper wet with solution as you work it gently over the headlight. You might want to mask off the grill with some cereal box cardboard or tape depending on how crazy you git with the sander. The headlight should be pretty smooth and almost clear. I have some Plast-X plastic polish and a Mother's PowerBall on my power drill. A little polish on the ball and start off at a slow speed. Eventually build up the speed and work it over the headlight. In no time at all, yer headlight should be nice and smooth and almost like new again.
You'll git more light on the road to see with! Just touch up the headlights once a month with some plastic polish and a microfiber towel and you'll be able git the max light out of yer headlights everytime.