Tips on getting off a bolt stuck on a toilet seat?

[y_p_w]

Waiting for a celebratory flush.

More than one.

 

[y_p_w]

Kohler sent the replacement part, I suppose as a warranty replacement part. Weird though as it doesn't look like anything I've seen before. It's in the blue and white bag that Kohler uses for most replacement parts with a clear plastic bag inside. No instructions at all. Then the label has the part number (1159527) handwritten on a pressure sensitive label. Two bolts, two of those plastic wing nuts, and two metal washers. Still can't figure out what the washers are for for the Quick-Attach seat hardware since no washer is needed for the hinge mount. Looks like this part:

https://www.amazon.com/Kohler-K-1159527/dp/B0BJTRQBGT
https://www.kohler.com/en/support/f...arts/hardware-kit-black-1159527?skuId=1159527

This will probably come in handy if the part eventually fails.