How to Install a Bi-Fold Door

Now you should have one pin left: the ridged pin.

Get off ladder. Unless you happen to have a couple of sawhorses handy, you can set the ladder on its side as a temporary sawhorse for this next step. Or simply lay door on the floor.

Lay bifold door across ladder. Insert pin on the end of the door that will be closest to the doorframe (i.e., the "hinge end"). Tap lightly with a hammer to get it all the way in.