The battery on my iPhone 3GS had lived a full and rich life and was ready to cross into the Pure Land. I was in a rush, made a quick internet check and ordered from iFixit. I realized the blonde in the videos was a complete fake-out. It was a blatant attempt to challenge those with geek self-image problems. If some blonde could do it, then why can't you? Or are you some kind of pseudo-geek? Pretty good job on the hair coloring though -- she looks like a real blonde.
The repair went well, and when I turned it on, it didn't really boot properly. It also kept resetting itself. An internet check indicated this was symptomatic of having installed the wrong battery. Not me, I'm careful about these things. A blonde would make that kind of error. Okay, so I actually installed a 3G battery in my 3GS. Ordered the proper battery, took the incorrect one out and the correct one in.
Doing it the first time is kinda spooky. Talking about the battery replacement here. Use a low power refrigerator magnet or two to hold the very tiny screws of which there are three types. The battery replacement comes with a screw driver and spudger so all you need is one of those suction cups to pull the screen off. The special order spudger is really good though. If you think of this as a skills acquisition project, you'll be slow and careful -- and successful!