Sorry I do not have step by step photos for this but I thought i would share this for starwars fans. This was a modification to an Ertl / AMT polystyrene model known as the "B1 Battle Droid with S.T.A.P." You can find it on eBay for about $20 shipped to your door.
Some features are: LED engines, landing strip and lighted sign. I also heavily damaged the STAP and the Droid. Sorry George Lucas, battle droids in Episode III look brand new, and I got to believe they are a bit damaged when returning from battle. I decided to build my own since all other store bought B1s seem too fake or "toy-ish" to me.
Assembly - Model glue, a good fine file, sandpaper, X-acto knife, clothes pins & tape to hold parts. File all the seams and sand like crazy to make seamless appearances. Take the time to do this and you will appreciate your model tenfold. Lots of youtube vids on modelling techniques so check them out.
Base - Smoked plexiglass sanded opaque epoxied to 3/4" plywood (routed out for raceway) glued over 1/2" plywood over felt. Oak trim with danish tonque oil finished it off.
Painting: I highly reccommend painting the entire model with black pain first via an air brush then add in the color then details. I really like the dry brushing in the silver to show scraped up paint. The sub-layer method of silver underside can cause adhesion problems of the over coat. Once fully painted a non-gloss clear coat locks it all down.
Wiring: 20 or 22 AWG braided wire for flexibility, Wire strippers, soldering iron, solder, soldering paste, 9 volt battery, push button switch, 100 Ohm resistors (3), LEDs each having a 2 - 3volt forward voltage drop range.
The LEDs are powered by a single 9 vdc battery in the base, ran through a push on/push off switch from Radio shack, then through three separate LED circuits to get the voltage drops as close as I could to 9 vdc. You must use a resistor before each LED circuit or the LEDs will burn out as they cannot control the current flow (it is like a dead short). Pair up the LEDs to get to a 9 volt drop as possible including the resistor's drop. See that I wired in the yellow stripe landing lights in the same circuit as the engines to get the best drop for them without losing too much drop in a resistor,
All LEDs have to be connected with the positive (longer) leads to the source and the negative lead (shorter one) connecting to the return leg or to the next LEDs positive lead. They are diodes that only allow current in one direction so if they do not light, ensure first you have a resistor upstream of the positive lead then the LED then the negative lead returning to the battery. Triple check your wiring is correct before gluing up the model or you will be very sorry!!! I ran the wires up into the model via an aluminum 3/16" diam tube. I expoxied it in the model and it holds just fine.
Lastly, if you choose to build THIS very model, AMT has a part mismatch / design flaw on the foot pedal mounts. They were waaaay to dainty to support the Droid and getting him mounted was a royal pain. So, I glued an extra piece of poly styrene into the mount then came from below the wing with a screw and screwed the mount onto the wing. It is very secure and works great. By looking at the mounting and the wing mold, it looks like they intended to do it this way but the mating foot pedal mold was tooled incorrectly to match up.