Dear friend
There isn't much of a secret at doing it. It is just a matter of connecting the cables in the battery (and making sure that positive goes with positive, black with black). If you have an original Yuasa battery, it may be a problem to install with the original screws (that are way too short). I solved the issue by getting some allen screws at Lowes.
In my bike, I installed a socket that can be used to power my Garmin Zumo *and* a USB adaptor that I can plug any cable into it (currently used to power my smartphone).
Some suggestions:
a) fused socket (136A, I can also use it to power a compact air compressor when I need and if I ever travel to a chilly place, can be used to power electric vests): $19
http://www.amazon.com/gp/product/B0068FYMVO/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1b) the USB adaptor (2.1A): US$11
http://www.amazon.com/gp/product/B00DJ5KEF4/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1Cheers
Savago