Below is a video on how to do it as well as a picture from Castle. If you go off the video let me point out two things I do differently because, personally, I think the way this guy hooks up a BEC is sloppy.
1) Instead of cutting your battery leads in two in order to solder the BEC leads in parallel, I personally solder the BEC leads to the battery connector along with the battery leads so I dont have to cut my battery leads on my ESC in half.
2) Instead of removing the red wire from the ESC connector, I place a short 3 wire extension on to the 3 wire lead come off the ESC so that:
A) I dont have to remove the red wire from my ESC plug and possibly risk damaging it and
B) I can remove the red wire from the short extension completely so I dont have a piece of wire all taped up to the main wire leads. Its just cleaner imo.
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