After having cases on my iPhones dating back to the 3G, I bought the 6 and thought "The otter box on this is way too bulky. Maybe I'll try one of those thinner cases.." Thinner case did not save my phone when it was knocked off the bed of my truck. Glass on the screen was shattered and was randomly slicing my fingers reminding me how dumb it was to not have a good case or screen protector.
Repair went off without a hitch. The iSclack worked great opening the display assembly from the case. The repair guides were well written and walked through each step.
Slow and steady is the way to go with everything. Take your time and make sure you get the cables disconnected and reconnected properly. Check out your replacement before assembly and make sure you have all the protective films removed before being stuck in the middle of your project.