But to remove it, you will see some mounting plates at top and bottom of the door and on the sill and top jamb. There will be some screws that, when removed will release either the plate in the floor / jamb or from the piece that cradles the door itself.

If you remove the cradle trim from the door, you will see a way to release the mechanism holding it in place. If you take loose the floorsill and top jamb plates, the door will lift away by lifting the bootom and swinging the door out.

There are more than one style and manufacturer so I can't be any more specific.