The battery in my iPhone 5s was failing.
I purchased the iSclack in addition to the iPhone 5s Replacement Battery / Fix Kit. The iSclack made opening the iPhone case very easy and eased my concerns about breaking the display. The kit was complete and with the magnatized bit holder made swapping bits easy, as well as picking out the screws. Not having steady hands made the reconnections and re-screwing very challenging for me. I did , however, complete the repair and was pleasantly surprised at job when all functions of the iPhone worked properly.
For me, a big help would have been to have a lighted magnifier, as well as figuring out sooner that the way to replace the screws was to use the smallest tipped phillips bit (supplied in kit) to grab onto the screw and once the screw was in place to use the proper sized bit to tightened the screw. I do not recommend using the supplied tweezer to grasp the screws, as it did not grip well and in fact did cause my screws to go shooting off.