Dig a trench along your garden bed. The trench should be deep enough so that the plastic edging goes down about half way. Each piece of edging should easily clip onto each other so assemble as you move along your trench.
Once your edging in is the trench, peg it into the ground on the back. Fill up the trench behind the edging back with the soil you dug out and then compact it to hold the edging firmly in place.
Roll out the corrugated garden edging and measure to the dimensions of your garden bed. Using tin snips carefully cut the edging a little longer than you need. Make sure you wear gloves to avoid the sharp edges.
After you have dug your trench, put the corrugated edging into the ground. It should go about half way down into the trench. Peg the edging in every metre, and backfill the trench with your dirt and you'll have a sturdy garden edging.