Bachmann sells the side frames by themselves, but they are out of stock. Are the frames cast in silver plastic,or painted? If painted, you could strip the paint off and try painting them black. You have to take the body off the frame.  Remove the wires from the trucks to the decoder board. There is a screw that holds each truck in place. Remove the truck, place a small flat blade screw driver on one end of the truck between the frame and truck assembly.Gently pry the frame away. You may have to do it to both ends.  If you look at the picture of the truck  you'll see a tab on each end. This holds the frame in place.   Joe 
https://estore.bachmanntrains.com/index.php?main_page=popup_image&pID=1371     https://estore.bachmanntrains.com/index.php?main_page=popup_image&pID=1372

I have their street lights. They're nice but can get pricey.   Joe

I believe the first 2 are for DC only. The third one is for DCC non sound.     Joe

Does this come with a keep alive installed? If yes, then it needs to be disconnected. The 1K ohm resistor  should work. You should look at a Digitrax PR4 and JMRI . JMRI is free and down loaded to a computer. The PR4 is hooked to the computer and a programming track. You can save your locos in a roster. This way, if you have to reset the decoder, all the CV's are saved and you reload them.   Joe

Or a spring from Athearn. Scroll to bottom right.   Joe
http://www.athearn.com/Search/Default.aspx?CatId=THCR&Page=7

I would say no. Bachmann F bodies have 4 posts on the body that fit into holes on the frame and are secured by screws.    Joe

There is no installation guide. On the bottom of the sound decoder sound decoder will be markings: HL+,HL- headlights. S+,S- speaker connection, RR,LR pick up wires from truck( one set for front one set for rear), M-, M+ motor connection, BL-,BL+ rear lights. Remove appropriate wire from old decoder and put on new decoder. I solder my wires as the plastic clips don't always hold the wires tightly in place. You may need to add wires to the front and rear leds depending on if they are soldered to the old board. Match the polarity as leds have a + and - leg.   Joe

With DCC sound decoders , on DC the loco won't start to move until around 7 volts or so. You will have a limited speed range.   Joe

Try programming it to another 2 digit address. If that works, then do your 4 digit address.    Joe

More great modeling.    Joe

Great job. Nice short video with good sound and great modeling. Liked your cab forward!!!     Joe

What model of loco?

It should be held in place by a screw or clip. If it's a clip, put a small flat head screw driver on 1 side of the clip a twist the side off. Then remove clip. Clip will look like this :
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_203&products_id=5896&zenid=f4hb0bl1q9dujdht40eq524vi6 

Joe

It should be an LED. Is it wires to the PCB board or are the wires held on by plastic clips? If clips, remove the 2 holding the wires on to make sure the wires are contacting the tab. Make note of where the wires go. LED's are polarity sensitive.     Joe

The orange wire is pin 1. The socket should have a 1 or some kind of mark to indicate where pin 1 goes. If the head light comes on, but loco runs backwards, CV29 can correct this.
CV29 calculater:    http://www.dccguy.com/wp-content/uploads/2018/01/CV29.jpg


Joe