threejacks-

(this is for soldering back of ESC to battery plug)
1- Use a soldering iron putting out no more than 40 watts, as it will probably burn up your wire.
2- The tubing is the heat shrink tubing that you must put on first, and when you finish your soldering, slide it down over the freshly cooled solder, and heat the tube to wrap tight on the solder, keeping the new solder from touching anything else.
3- Make sure you have stripped the wire so that you have enough to solder with (a quarter of an inch should be enough), twisting it to a shape so that will fit to the pins.
4- Make sure the the pin you are soldering the wire to is hot enough to keep the wire melted to it. solder the wire to the outside of each pin, as this is probably the easiest. It will be a delicate process, so if you know anyone who has experience w/ this, maybe they should do this part.
5- After you have soldered the wire coming from the back of the ESC to the plug, slide the heat shrink tube (mentioned in 2) down and heat to shrink around wire.

(This is for soldering the three wires (Red, white, and black if Castle 25 speed controller) to back of motor)

1- Strip wires sufficient enough to be soldered.
2- Slide heat shrink tube over wires before soldering
3- Slide wore into plug on back of motor, and solder though holes in brass plug.
4- Slide heat shrink down and heat to shrink over solder

any more questions post again,
Good luck