I just took mine off because I took my rear tank off and suspected the switch unit was causing me issues with flow. But, I dont' understand the reason why there are 2 lines from the tanks. 4 into the switch unit, 2 out-you just unclip the electric cord and then the 4 lines all have a safety clip you have to use a flat screwdriver to pop that out and then the lines come free. Prepare for gas flow, or remove the connection on the top of the gas tank, but some will still be in the lines. I ended up cutting off the plastic ends and using 3/8" fuel line to couple the plastic lines together.
there's the extra lines because one line is for feeding the motor and the other is a returns line.
as far as changing out the fuel selector vavle (and assuming yours is equipped with the mechanical one that has the 4 lines pointed toward the rear and 2 toward the front) you'll need to remove (I think 3 10mm) bolts to loosen the valve. Then pull the clips off for each line and the lines slip right off. Wait a while after you shut off the motor before doing this as it will remove more of the fuel pressure. Lastly, be REAL careful when removing the clips and sliding off the fuel lines. The nipples coming off the valve can break pretty easy.