LED Strings using BOE with BS2

I have a couple strands of 12V LED lights that I would like to run from my BOE and BS2 stamp. What is the easiest way to do this? I have external power for the LED's and I just need to know how I would connect them to the BOE board and what all is required.
Comments
There's information about using a relay and high power transistors in this N&V article.