The repair section on autozone.com explains how to change the light switch.
You can purchase a vinyl repair kit to remove the scratches. You can also use silicone to fill in the scratch, and buff it out.
It would be best for you to buy a Haynes Manual as it will have everything you will need to do the repair.
Try the repair tips on the Autozone web site.
The Heater Core is behind the dashboard and is very difficult to replace. The entire dashboard must be removed to facillitate repair. There is another web page which I have that details the dash removal procedure. As soon as I can I will submit the procedure to this website.
How to remove the heater core: Get Haynes repair book #24071 at your local parts store or on line at http://www.haynes.com/products/productID/242 The $24.95 PAID FOR ITS SELF with just this one repair. Local repair shops wanted $300.00 Plus to do this job. It took me about 6 hours to do this by myself. Hope this all helps! Assuming coolant has been removed, heater hoses have been disconnected from the heater core: In short, disconnect battery, wait 15 minutes. remove fuse for airbag, wait 15 minutes. Slide driver and passenger seat as far back as possible. remove 4 bolts holding steering column. (it will tilt down and rest on drivers seat) remove all the underdash vent covers, remove the bolts located on the "walls" under the dash. remove control panel covers and remove the radio. (tie a long string to radio anttena coax, you will use it to pull coax back through the dashbaord later, this was not mentioned in the book and I learned the hard way...) pull defroster vents off dashboard, remove speaker covers. you now need someone to assit!!! remove the 6 small bolts found under the defroster and speaker covers and dash will fall forward. disconect the wire harness connectors, 2 of them i belive. on drivers side. On the passenger side, disconnect the LARGE wireing harnes using a deep socket( forget the size, but it is a metric, #10 I think). the bolt that secures this large connector to the dashboard is located in the center of the connector block. Now you and your helper lift the dashboard out and back slowly, checking for other wires, etc. now remove the 6 - 8 screws that hold the heater housing cover in place. remove the 4 screws that hold the heater core in place. remove and replace heater core. reverse steps to re-install dashboard.
Get a new dashboard!
Try the repair tips on the Autozone web site.
The dash has to be remove and the evaporator/ heater case has to be removed and separated. This job is best left to a repair shop.
There is a detailed explanation of how to remove and replace the dashboard bezel to replace the lightbulbs contained in the Repair Manual, which is unfortunately too lengthy to reproduce here.
you must remove the dashboard, instrument cluster, passenger airbag, etc. remove the heater and ac evaporator cover, http://www.f150online.com/forums/showthread.php?t=215665 this will help well first I'll make the point that the question is for the REAR heater core and not the front on which the person failed to see. To fix the issue, I have not had any issues with mine(98 Expedition). Either buy the owner's manual/repair guide and that should help.
Water Heater Repair Seabrook TX