Insert the rod frame that come with the bag into the open slots in the bag. Slide the rods in until the square end of the frame touches the bag.
Slide the plastic channel catch on the bag over the metal frame to secure it in place.
Lift up the plastic flap at the back of the mower to expose the blade.
Slide the metal catch on the end of the metal assembly on the bag onto the pivot rod underneath the plastic flap.
Let go of the plastic flap so that it rests on the bag.