Replace Section Of Carpet Pad
Press it over the damaged area and turn until you reach the padding then pull out the circular piece and patch as you would a large section.
Replace section of carpet pad. Remove the old carpet pad. In either event be prepared to vacuum up a lot of dirt and possible degraded carpet pad. A line or 2 of glue on the surface of the carpet pad will often be sufficient. Older carpet in high traffic areas might be more faded.
Using a razor knife cut around the section of padding you are removing so you can pull it away from the rest of the padding. If a section of your floor covering has seen better days remember that you can patch carpet saving the considerable cost of replacing the entire thing. If carpet tape is not doing the job you can also use carpet glue to hold the patch in position.