Hold the edge flat against the floor with one hand and position a piece of furniture over it to help flatten the edge. Leave the furniture on the rug for about 30 days to straighten it.
Steam the carpet if it is still curled after a month under the furniture. Position a towel over the curled edge.
Add water to a clothes iron with a steam setting and set the iron to wool. Wait for the iron to heat up.
Straighten out the carpet edges with the iron; this helps loosen up the carpet's fibers. Only iron the carpet on top of the towel.