5 - 30 minutos
My Iphone 4 speaker enclosure got splashed by some liquid and stopped working. I no longer have a valid warranty, so a return to Apple tech support would have cost me a small fortune. Decided to get the parts from Ifixit and do the replacement myself, and thought of replacing the quickly waning battery to save the time of another operation.
The guides were detailed and comprehensive, and it was quite a pain free process. it took me slightly longer than I expected, partly due to the screws being so tiny. I did not have an Ipod opening tool, but managed ok with my fingernails and a pair of tweezers.
Now my Iphone is as good as new!
I had some problem with wi-fi reception after the repair, and had to open up my iphone again. the problem was the 4.8 screw attaching the wi-fi antenna, so make sure it is secured well and tight. The wi-fi reception is fine after this minor follow up.