The following steps demonstrate the installation of the portable pet door.

STEP 1 . . . open the glass sliding door to make way for the portable pet door.

STEP 2 . . . . push the portable pet door into the same rail track as the glass sliding door.

Push it first into top rail and then drop it into the bottom rail . .
Now the pet door is sitting next to the glass sliding door.

STEP 4 . . . Close the glass sliding door against the side of the portable pet door

You're door is ready to be used! It's that simple!