I know it takes patience. Stick with it and the gains will come!
Step Three: The Slow Lower
Using a step, position yourself so you can easily get up above the bars without expending too much energy. You will lower yourself ALL the way down with as much control as possible. The focus on this step in holding and controlling the lowering stage of a pull up.
Do the lower 3 times, allowing a rest break in between each time. 3 sets of 3 lowers each day.