The flat end of the battery goes in to touch the spring. I say this because I had to guess it: the part of the packaging with "instructions" is in completely senseless Sino-English (though of course perhaps also in excellent Chinese...); and I can only hope there is nothing important that I need to know to use it fully: there are some four tiny switches on both the transmitter and receiver...and I have no clue what these might be for.
I had thought, when buying it, that the part with the cable was a "clicker" and the other bit the remote - but actually it only works as a remote: the transmitter with the antenna; and the bit with the cable a mere receiver connected to the camera.
It seems to work quite simply: half press of button focusses - next click takes the shot. On continuous mode I clicked and it fired off an endless stream of shots, so I could only turn off the very power of the receiver to stop it (perhaps the mystery switches have something to do with this?...).
Otherwise, I just hope this expensive type of battery lasts long.
I have given it three stars because, for now; and having asked so far only the simplest of it, IT WORKS.
The tiny switches (incase anyone might understand them) are numbered 1234; and on the transmitter say ON AJP and on the receiver ON KE. Any ideas? - please comment. (ps. after a good time of use, I now give it 4 stars [one off for the instructions])