5 - 30 minuten
My older Iphone 4 wasn't holding a charge really all that well. Sure the battery lasted for a day when moderately used but it would shutdown at around 10% instead of 2% like I wanted. The thing that told me 'time to swap that battery' was when the battery got REALLY hot during a charge recently. Now it was a safety issue.
What killed my Saturday was it was to easy Friday night. I got the Kit (with the tools and the battery) in the mail Friday and decided "I will make that my Saturday project." I was thinking 'to do this right will take some time.'
However after watching the video guide on iFixIt I said the fated words of "wonder how hard it is?" Turns out, really easy. I got curious and pulled the back off (1/5 difficulty). Started pulling on the tab to release the battery (didn't budge), used the pry tool to get the battery loose (2/5), popped the connector (1/5) and the next thing I knew all I had to do was put the new battery in. Pulled the new battery out and dropped it in (0/5), connected it up (1/5), put the cover on(1/5), and screwed in the Liberator screws (2/5 [stupid small screws]).
Powered up the phone and went "Aw shucks!" No the phone was fine, I just realized I had already completed my project for Saturday that Friday night. Yes, that easy. Took about 6 minutes from when I first opened the kit to when the phone was powering up off the new battery.
Got any nitrile or food service gloves at home? Slip those on as you can reduce the chances of touching any part of the phone. Then you might not need to do a thorough alcohol cleaning. Watch where you touch. Use the plastic pry tool to interface with the connector rather than your finger.
Also if the battery doesn't pop out with the tab, follow the advice and just pry around the battery with the plastic pry tool. Make sure the battery connector is popped of first. That battery, regardless of age, is still pretty tough and can take some prying. Give it a little (note LITTLE) force until you hear the glue start to give. Just continue that, alternating locations, around the battery. Should, on one pry, pop right up and be free.