5 - 30 minutos
The phone went down with my niece in a hole in the ice.
My niece survived thankfully but the iPhone battery did not.
Followed the guide and it went very fast and super easy.
Make sure to buy the Philips #000 I thought it were only needed for the exterior screws. Luckily my neighbour had a screwdriver to lend out. Otherwise I would be unable to finish the repair with the parts I ordered from iFixit.
Phillips #00 Screwdriver
P2 Pentalobe Screwdriver iPhone
iPhone 4 Replacement Battery