Its not too difficult mate, basically its a static balancer, the same type as they use at bsb etc, the wheel is locked into position on the bar via 2 cone shape fittings, this is then placed onto the frame, which has 2 rollers to allow the wheel free spin.
You let the wheel find its own balance after removing any existing weights, and the heaviest part will settle at the bottom, once i have found this, i mark the tyre directly opposite the heavy side at the top at the lightest point, you can then begin to add your weights here, spinning the wheel slowly until i find that wherever i place the wheel in rotation, it stays still, thus balanced
Also if you find yourself with a few weights, they can be added to both sides of the rim, hope this explains it, cheers Wes