That... doesn't look easy. Or at least, I imagine this video would look intimidating to non-tech savvy users. I consider myself at least a little tech savvy and I'm like 80% sure I would forget to insert that transparent sheet thingy under the battery. I'm guessing it's insulation?
Anyway, what used to be the norm was pulling off the back cover and then remove the battery with your fingernail. No tools required. Now a vast majority of phones are glued together, all under the pretext of making the phone more thin.
What irks me is that companies still make removable batteries, but they are getting harder and harder to find. In fact, Samsung itself has XCover line of phones that have easily accessible batteries. How easy? This easy:
https://www.youtube.com/watch?v=Zb7N60P51q4
(Actual battery removal at around 0:11)