remove the red wire from the HIGH tap, resolder the red wire that is on the normal tap.
remove "if you want to" the short black wires, and solder blk wires directly to 3rd lug on transformer.
same for the black/white wires, but to 4th lug.
Remove the white wire from the transformer bolt, I believe that is AC hot, not to be grounded.
where does that loose red wire go?
Hot from power cord through fuse to left bottom lug on transformer.
Neutral from power cord to right lug on bottom of transformer.
Ground from power cord to transformer bolt.
That shud get you started