Find the two small wires that move your solenoid. You can do so by shorting those small wires one at a time to the large lug/wire on the solenoid to find out which one is in and which is out.
Run both of those wires into one side of a double pole, single throw switch (4 terminals). Out of that switch, run the wires into a single pole, double throw switch. The DPST switch will be your on/off. The SPDT will be your in/out. From the SPDT switch, run one wire, fused, to your fusebox or to your battery directly. Put the fuse as close to the current source as possible to avoid a fire and to protect the wiring. I will draw you a schematic when I get a chance, it's really pretty easy.