Seat cannot be removed, installed or won’t swivel

This is caused by the seat swivel release lever being jammed. It was jammed because the seat was improperly placed on the seat post.

Proper way to place the seat:

You must pull up / squeeze the seat swivel lever against the seat before placing the seat on the post.

To unjam the seat, you’ll need to alternately squeeze and release the seat swivel lever as you lift up on the seat.