Remove everything from your old shelves then remove the shelves.
Remove the cupboard door by pushing in the button in the back of the hinges. Clear out the cupboard.
Attach the top sliding bracket to the top of the frame – it will just clip on. Don’t attach the bottom bracket yet as it needs to be attached to the side of the cupboard.
Fix the bottom rail into place - make sure you place it just back from the door so it doesn’t get in the way.
To do this, place the bracket in place and screw the two front top screws in, followed by the back two and then the bottom screws. Mark your holes first and pre-drill them with your 2.5mm drill bit before inserting the screws. If you are working in a narrow cupboard getting your drill in at the right angle can be tricky. If your drill is too large to fit, you can get handheld 90 degree ratchet screw drivers. It is also helpful to place a temporary packer (a block of wood about 100mm high) underneath the bracket to help hold it in place and get your drill underneath to fix the screws in.
Now slip the frame into position, clipping the bottom part into the rail. Attach the top bracket into place with screws like you did the bottom bracket.
Clip the door back on, and fill your cupboard.