Re-screening a sliding glass door is one of those inevitable household projects, especially if you have children or pets.

The easiest way to replace a screen that has been torn or is bowed is to hire a professional. Choose any contractor carefully, or you’ll end up paying twice for an initial job that was poorly done. But replacing the screen is actually fairly easy to do yourself, if you have patience.

Here’s what to do:

• You’ll need a new screen, spline, a spline tool, and a utility knife. It’s best to work on a table, but a driveway or patio will suffice if you don’t mind being on your knees.

• Remove the sliding door from the sliding frame. This may take a little jiggling. Lay the door flat and use the screwdriver to pry loose the spline, which is the black cord that holds the screen secure in the channel of the door frame.

• Remove the damaged screen and lay the new screen on top of the door. The replacement screen should overlap the door frame channel by at least a couple of inches.

• Use the spline tool to roll the spline into the door frame channel, taking care to keep the screen taut. When you come to a corner you can either cut the spline and begin a new line, or continue around the corner with the same piece of spline. You may need to insert the spline around the corner with the screwdriver.

• After the spline has been inserted, trim the excess screen with the utility knife. Make the cut just above the spline line.

Reposition the door into the slider. Depending how rambunctious your dog or kids are, your refurbished door should look like new for a few more years.