Dynamo hubs

Hub to front light
Front light to back light

All wires and connectors should be in the various boxes but if not, eBay is your friend.

Use sugru or tape to keep wires tidy.

The headlamp will have a long pair of wires (joined for lost of their length) and a short pair of pigtails. The long one goes to the hub. There should be a free length of wire with some spade terminals at one end. That goes to the rear. Fit the terminals to the pigtails on the headlamp and trim to an appropriate length (not necessary, purely for neatness). A pair of unattached spade terminals will be included somewhere. Strip the insulation off the wires going to the rear (a penknife should be fine), slip the terminals onto your wire and crimp the terminals with pliers. Attach to rear light.

Note - the rear light doesn't care about polarity (so it isn't marked) but the front does. Check the B&M instructions for which wire is Earth/negative (normally had a white stripe) and attach to the correct part of the hub fitting.