Can anyone who has them tell me how much is involved in removing the useless power extending ones (Power Vision) that came on my 2005 GMC and replacing them with the Schefenacher mirrors?, I know they are not going to have the power extending feature like the Power Vision but the power adjust along with the heat and turn signal feature will work just fine as long as I can see better when towing, also will I be able to use the existing plug or will I need to install another wire?.

Did you already buy the mirrors? Did you consider the stock 2006 towing mirrors? They are plug-n-play and better IMO

I have installed them on two trucks (still have an old set for sale) Very simple to install, you need to purchase a harness with the mirrors that will allow them to plug right in to the factory mirror plug. After that the turn signals, heat, and aiming controls will all work just like the factory mirrors did using the factory controls. The hardest part of the install is removing the inside door panel. Remember that after you have take out the screws, the door panel lifts UP to disengage from the door, it doesn't use the snap in pins like the older trucks did. The mirror itself is only 3 bolts holding it to the door. Install start to finish should be a couple of hours.

You can't go wrong with those mirrors, WAY better view than the POS stock extending mirrors. They don't vibrate like the factory mirrors and are a little bit wider making it easier to see around an 8.5' wide trailer.

X2, the Schefinacher TTT mirrors are very nice. After you get the correct interface harness it's plug and play. The only extra wire you would need to run is for the clearance light feature.