My new to me Blazer has these on all 4 windows and I despise the look. I tried removing one, but it just broke. If I pull too hard, I am worried they'll take the window seals with them.
Pull them starting from the corner. Slowly apply more and more pressure until you start to hear the tape peeling away. It could take 1 minute per visor to peel them off. I've never had an in-channel visor break...
Not sure on the difference between channel and full tape on, but I am guess full tape on. They are just adhered to the window seals. Sounds like I'll give the heat gun a try.
The truck probably hasn't been washed in 3+ years. I used about $7 in quarters yesterday just do get crud out of all the seams. These darn visors do a great job holding crud too.