Replacing worn or damaged weather stripping around exterior doors will save money on your energy bills.
Take a piece of the old weather stripping with you to the home improvement store so you can easily match it.
The weatherstripping in newer doors fits in a groove in the door casing. To remove it, simply pull it out.
Then cut a new piece to length, and insert it in the groove.
Older doors can be retrofit using rolls of self-adhesive foam weather stripping from The Duck Brand.