My really old iPod Touch is new again!
1 - 3 hours
My issue was a weak battery, the battery wouldn't hold a charge for more than an hour or so.
I followed each step to the letter and I had no problems removing or re-installing the battery.
I had to perform a factory reset due to a completely white screen upon initial power up. I found a video online on how to do said reset, I think I held down the home and power buttons for 10 seconds or so and voila! Also don't use a razor to scrape off the old glue or you'll end up scraping of some of the black paint off. Despite the mishap with the paint and the reset everything works great.