The easiest and most efficient way to repair leather headboards is to acquire a new piece of leather to mount over it. Stitching, using a liquid gauze or using some type of leather paint when trying to repair leather usually results in a lackluster to poor outcome. If your leather is separated into panels on your headboard you can cut that section from the headboard and simply replace that piece. Otherwise, plan and getting a piece of leather large enough to remount the entire thing.
Step 1 - Remove Damaged Leather
In order to effectively repair your headboard without causing further damage you will need to separate the headboard from the rest of the bed. Depending on the size and type of the bed will depend on the difficulty of doing this. Consult the instructions or contact the manufacturer to figure out how to do this without damaging your bed. Commonly the headboard is attached by screws and can be detached by a screwdriver, or it is fitted into place by design.
Step 2 - Remove the Leather
The leather on your headboard can be attached to it in a couple different ways. The trick is to remove the leather without damaging the headboard, which can be done if you are careful. If the the leather is stapled to it simply use pliers and carefully pull them off. If they are tacked on with decorative tacks that your wish to use again then use the end of a flat-head screwdriver, gently pry the tack slightly off the headboard, then use the pliers to remove it the rest of the way. MAKE SURE to try and leave the leather you are removing as much in one piece as you can. If the foam under the leather is damaged as well (if you have foam underneath the leather) then remove that as well.
Step 3 - Measure and Get Materials
Once the headboard is detached and the leather is off measure the leather you have removed. Add at least 2 1/2 inches to each end of the leather you have removed. Purchase a cut of leather that has the added measurements on it or cut the leather to the appropriate measurement.
Step 4 - Attach the New Leather to the Headboard
Lay the new leather face down on the floor so you can lay the headboard on top of it. If you need to replace the foam attach the foam first to the headboard by cutting it the proper length and attaching it with spray adhesive. You must wait until the adhesive is dry before you replace the leather. When you are ready to attach the leather lay the headboard face down on top of it.
Pull the edges of the leather over the edges of the headboard. You should have the 2 1/2 inches extra from your prior measurements. Fold back the edge of the leather you have pulled over the headboard so that the underside of the leather is exposed. Use the staple gun and use 1/4 inch staples to staple the leather to the headboard about 6 inches apart. MAKE SURE you are stapling the underside approximately 1 inch from the fold. You should have 1 1/2 inches excess leather from where you stapled. Use the spray adhesive and carefully spray the underside of the excess leather then fold the excess leather back to the good side at the stapled mark. This gives the back of the headboard the appearance of a professionally done job and will cover where you had stapled the leather to it.