Ok here's what you do. Get about 5 or 6 cotton balls, an old T-shirt, a rubberband, a medicine dropper and some dye. Thin your dye to a lighter color than your after. (it's better to add more than to go too dark up front). Cut out a piece of the T-shirt into a 5" or 6" square. Place the cotton balls on top and collect them in the t-shirt and gather the t-shirt like you do a garbage bag. Gather it tight and then use the rubber band to hold this together. Now you should have a "pad". Use the medicine dropper to add dye to the pad, blot it to get the excess dye off then, starting in one corner, rub the pad on your leather in circular motion until you cover the entire piece, adding dye as you go. You'll know when you need to add dye. Do this in several coats to achieve the desired color. This method is called burnish dying. I've had fantastic results using this method.
Good luck,
Marlon