Summarize:

If the person is not conscious, you will need to give them an injection of glucagon. If you are not a medical professional, then this should be done by a family member or friend who has been taught how to give the injection.  Call an emergency number immediately if no one is able to give the injection. Glucagon requires a prescription. If you are a diabetic, make sure someone around you knows that you have the prescription, and show them how to give the shot. If the kit is still usable, open it and take out the contents. Mix the glucagon powder and liquid, carefully following the directions on the box.  Do not give expired medication. Instead, contact emergency assistance. Keep the glucagon stored at room temperature. An injection of glucagon may cause the person to vomit. To keep the person from suffocating in the event this happens, turn them on their side. Use an alcohol swab or a cotton ball soaked in rubbing alcohol. An easily accessible spot would be the upper arm. Let it dry for a few seconds. Tap the syringe gently with your finger to check for bubbles. If any appear, push the plunger slightly to force out the air. Pinch a fold of skin in one hand. Hold the syringe close to the fold with your fingers off the plunger. Stick the needle into the injection site. It can be injected into the subcutaneous fat or into the muscle. Quickly push the plunger in completely and give the amount stated on the kit's bottle. Usually the syringe is held at a 90-degree angle, however a 45 degree angle is often needed for small children and thin adults. This is to prevent the injection from going into the muscle. Be sure it is being removed at the same angle it was inserted. Place the cover back over the used needle. Dispose of the used needle in a sharp disposal box or a hard container with a lid, such as a laundry detergent bottle, as soon as possible. Use the one-handed needle recapping method to prevent accidental needle sticks. Place the cap on a flat surface, then insert the syringe into the cap using one hand. Push down against the cap until you hear the "click." Glucagon should act fairly quickly. Within about 10 minutes of receiving the injection, the person should wake up.   Call emergency services immediately after giving the injection. Glucagon will temporarily stabilize the person's blood sugar, but they still need to be evaluated by a doctor. Be prepared to clean up in case the person vomits. By the time 15 minutes have passed since the injection, the person should be able to swallow. Give them something with carbs and protein as a snack.
Find the person’s glucagon supply. Check the expiration date on the emergency glucagon kit. Place the person on their side. Clean the injection site. Ready the injection. Insert the syringe. Remove the syringe slowly. Wait for the person to wake up. Give the person something to eat.