That would work
I went both ways, all the way out and back in, and no fluid came out...i bet it's clogged. I've been reading a zip tie poked in there can free up a blockage.it screws in towards the radiator to open the wing nut stem.
I still have to cut it regardless though. The radiator wire and whatever the other black is Are joined under that connector thing.loosen the allen hex set screw and pull the wire from the battery clamp.
edit if that doesn't do what you need cut both right at the yellow butt connector, when you go back together we'll think up a better way.
www.alloyworksplus.com
It's the one I bought for my c10.. so far so good...Seems likeca nice radiator. Web site is well designed and gives good information.