I put one on my dads truck tonight, 15 min and other than the diesel bath I got it's great. No drips after a 2 hour trip. Nice being able to use the other tank again. It took longer to type this up than it did to do the job.
Now he's got to carry a extra spare filter with him as he starts to use the previously non-functional tank again as it's been quite a while and the diesel that drained from that line smelled suspect.
I would suggest that one learns about how the the plastic locking clips work before one starts digging in there with a screwdriver. I will note that there are 2 sizes of clips, black and opaque, the opaque ones are commonly available at napa and other places. Not sure about the black ones. Once you figure out how they lock into place it's not difficult to pop them out.
Procedure is:
-Unbolt the unit from the frame (so you have some maneuverability to reach all the lines). Note that the switch body has nut-serts pressed into the plastic, it's possible and common for these to pop loose while loosening the bolts. You may need a wrench and some creativity to get them out if they break the switch body plastic or you can't get them to stay in place while pulling out the bolts. You might want to soak them with penetrating oil a few days before trying this and to top it all off, the nut-serts seem to be some kind of locking thread so the threads are tight all the way out.
-Undo the electrical connector and plug in the new switch while it's hanging there.
-Operate the new switch a few times to make sure it's working correctly; you can hear and feel the motor moving the valves inside.
-Pull out all the locking clips on all the lines. You may have to remove one of the top lines headed to the motor to get access to the last clip or two but luckily that one doesn't drip much if the truck has been off for a while.
-Get the new switch ready to go in your off hand, oriented in the correct direction.
-Remove the top lines, Bottom lines, and then pull the old switch forward off the rear lines. Be ready for your bath.
-Stuff the new switch onto the rear most lines as quick as possible, hopefully they didn't swap places like mine did in the heat of the moment; then push on the bottom lines and finally push on the top ones.
-Re-install all the line clips noting that the black clips go on the three lines closest to the frame and the opaque ones go on the lines closest to middle of the truck.
-Plug in the electrical connector if haven't already done this. Note the electrical connector is a really tight fit btwn the frame rail and the switch body if the switch is bolted tight to the frame.
-Bolt the new unit back to the frame and motor on with your life and re-activated fuel tank.
If your truck is really dirty under there, I'd recommend power washing that area before you get started to minimize the possibility of dirt intrusion into the fittings and your eyes.
If one of your tanks has been unusable for a while be extra sure to carry a spare fuel filter or two and wrench with you. Keep an eye on the little red Fuel Filter light on the dash you might actually see it light up if the algae clogs get bad.