do I have to run them out to the battery or can they be hooked up inside the cab to a 12v constant and a ground somewhere?
I'd find a point of constant power from inside the cab and same for ground. Or you can run a power feed to the BJB under hood. One source you could use is the Cig lighter power feed. But where ever take power from be sure to put an inline fuse next to where you tap.
As for making connections/splicing there are several different options. Scotchloks, crimp, or solder.
This diagram may help you understand how the five wire system works on a CLS. Note this is just the CLS Module, but the actuator wiring is the same. Only difference in modules is having the keyless built into it verses this one being connected to an alarm or keyless system.