Orren, the black arm needs to be free, what it does when you pull the fuel shut off the rod in the cover pulls the black arm back, which turns its shaft where the nut is behind the retaining plate with the two screws, on the end of the shaft is a little flat headed pin that transfers the shaft movement to up and down movement of the slide valve on the Head unit which opens or closes fuel to the head unit.
See my post #8 in this thread for tm illustrations, on the head unit picture the flat headed pin plugs in where the slot is labeled A.
See Gimpyrobb,s post #10 for real world photos of the arm being disassembled.
If it is froze do not force it as the little flat headed pin may get sheared, you will need to remove it, you already have the rod and clip disconnected, before removing anything I usually take a rag (an old t shirt works great) and put it down like a blanket tucked under the IP and up the fender to catch anything like the clip you already removed or the little flat pin etc.
take off the screws and retaining plate, then you can pull the shut off arm/shaft like in Gimpyrobb’s above pics, you will see the flat pin on the end of the shaft, now with a flash light and mirror (or looking through the fender vent) you can see the flat slide valve, spray your favorite break free lubricant in there through the hole, now work the valve up and down until it takes virtually no effort with a small blade screw driver.
when you put it back together lube everything with light oil and check the condition of the o ring seal on the shaft I lube it too, when putting it back together it will be a pain the first time you do this probably multiple attempts you must line up the flat pin with the slot in the valve on the hh, also the plate with the arm/shaft with the two holes in it has a top and bottom it must go back with the same side up or it will not clear the cover gasket.
I have found for me It makes it easier to put a little oil in the flat head pin's hole on the end of the shaft so you can use the slight hydraulic action to pull the pin out a little to help line up engagement with the valve on the HH unit.