Can you access the nut underneath or is it captive?
On my trads I use an open ender, vertically onto the bolt head. The other end is a ring, so I use a tommy bar through that, but it works with an open ender at both ends, but is slow, and tedious.
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
