You can find instructions for doing that on a Fire tablet in my 2017 guide on hacking Amazon Fire tablets. And there are more details about the state of Fire HD 8 hacking at the xda-developers forum.

And one of the most useful tools for hacking Amazon’s tablets is a free third-party utility called Fire Toolbox. Amazon Fire HD 8 (2020) with Google Play) ...

The shortcoming of Fire tablets is that even though they're technically running Android at their core, they don't have access to Google's Play Store, instead relying on Amazon's smaller and more ...

Tweaking, modding hacking -- it's all part of the tinkerer mentality. And at $200, the Kindle Fire is a natural choice for a low-priced starter tablet to hack.