Removing the battery was a challenge as the old adhesive snapped before it came out so I had to use a hair dryer to warm the adhesive before slowly peeling the battery off. I still manage to puncture the batter and nearly had a fire. When inserting the new battery I didn’t leave enough room for the connector to fit beside it so I had to pull it off, plug the connector into its port, then insert the battery. I think the instructions should warn you to leave enough room for the connector to tuck in beside it.
The kit came with a new adhesive gasket but I could not find the instructions on how to install it. But after 45 minutes I had it done and my iPhone 6S is back in working order. Don’t forget to ‘hard’ reset the phone on start up, run the new battery all the way down. Otherwise this is a very good value time and money wise.