


If you want to repair it then you'll need a screen repair patch kit, available at most hardware stores. Around $5 or so.
If you're going to replace it then you'll need screening (comes in a roll), spline (the rubber rope that keeps it in place)and a spline tool. All in all about $10-$20. Keep in mind that you'll have enough spline and screen to fix more than one screen and the tool is yours forever or until you lose it. Replacing the screen is more work but you do get a more finished look and you probably won't ever have to do it again. If you patch it instead, you should get a few more years of use but you'll always notice the patch when you look at it. It'll "bug" you until you break down and replace the screen.
Here are the steps to your screen repair.
1. Locate the culprit screen
2. Remove the screen and close that window
3. Lay the screen on a flat surface or stand in an out of the way place.
4. Open the patch, the one you bought earlier, follow the directions per the package.
5. Replace the screen into the window.
6. Voila! No more bug bites from that hole.
1. Take out the screen and close the window.
2. Use a flat screwdriver or your awl and remove the old spline and screen. Trash 'em.
3. Open the new screen and measure out enough to cover the frame with a few inches extra on all sides. Cut what you need and roll up the extra for another job later.
4. Lay the new screen over the frame.
5. Open the spline package and measure out enough to go completely around the frame but do not cut it yet.
6. Insert the end of the spline into a corner of the frame over the new screen. Using your hand and fingers, push the spline into the frame for a few inches at a time until you have one side of the frame done.
7. Now use your spline tool and drive it deep into the slot of your frame. Once one side is done, check to make sure that the screen is still in the correct position. You want the screen to be tight but not too tight, just enough to bounce a quarter on.
8. Continue to do this on each side until all of the spline is in. When that's done you can cut the spline off of the spool.
9. Now, using your utility knife, trim off all the extra screen as close to the spline as you can get. Be Careful! The knife should be very sharp.
10. When you're done trimming, replace the screen into the window.
You're done!

Now you can be confident that when you open your windows to let that beautiful fresh air into your home, you won't get bugged!