If you remove the seats it a whole lot easier to work. My 2000 i have a squat sensor wire and 4 nuts and it comes right out. Frankenstein is a 2020 and has airbags in the seats. I found you do not have to disconnect the battery to disconnect seat airbags just be sure that the key is off when you disconnect them. Also you can drive the van with the seat airbag disconnected (as in passenger seat still out) you will have a warning light on the dash but it will go out once the airbag is reconnected. It appears by the video below that that was 2 Allen screws holding your pulley on. Looks easier to remove yours than mine. Sometimes mine rusts on and the bolts to remove it shears off and i have to use a puller. Yours the only consern would be to make damn sure you have the proper Allen wrench and it seats properly. Cause if you strip um out it'll be a real pita to deal with. Glad to hear you got it off ok
Air bags in the seats? What the heck do those do, eject you out through the roof like a fighter jet before it crashes?!
I had a feeling a perfect fit was important. I actually drove to the hardware store and bought an appropriate long allen head socket for that pulley. My metric set was too wiggly. After I fixed the blower mounting bolt I realized I need to put the pulley and belt back on separate because the pulley and bushing need to line up perfect and be seated on the shaft perfectly. I ended up loosening the pillow blocks and did your recommended trick using longer bolts to get enough movement on the lower pulley to put the belt on.
I got it all fixed up! Changed the blower oil and removed the salsa heat exchanger and soaked it degreaser and cleaned it out while I had the driver seat out. At first the blower belt was too tight, but it was quiet when I ran it. Then I overcompensated and the belt was too loose and began squealing when I ran it. Then read the manual again and learned the belt needs 1/64" deflection per 1" of span, so a little less than 1/4" deflection on my setup. I think I got it right on the last time. Now it's quiet and isn't scary tight.