Not too bad.  This will require you to secure the rack at the bottom as well.  Otherwise, it is not as secure as you would want it to be.  The hardware to connects the two rails was just ok since the two bridge pieces did not exactly match.  Not too big a deal but presented a slight annoyance during assembly.  In the end, it accomplished my mission of organizing spices on the door.  Just don't forget you will need to secure it at the bottom as well.