I had to use special tools to remove the batter from the iPhone 6 I owned, but that was back before they started gluing the battery to the screen. It only took 15-20 minutes.
Looking at the ifixit guide for iphone 6s[1], it doesn't look like you need any special tools (as defined by the regulation). Sure, they're not exactly tools that a typical person has in their toolbox, but they're all "commercially available". ifixit even offers them for sale in their guide.
Didn't they redesign the interior of the iPhone 14 (normal) to be more easily repairable? Not end user repairable yet, but more than previous designs? I guess they make first steps in that direction.
Looking at the ifixit guide for iphone 6s[1], it doesn't look like you need any special tools (as defined by the regulation). Sure, they're not exactly tools that a typical person has in their toolbox, but they're all "commercially available". ifixit even offers them for sale in their guide.
[1] https://www.ifixit.com/Guide/iPhone+6+Battery+Replacement/29...