- Unlock bootloader (depending on vendor, you have to do an online verification),
- flash a recovery.img,
- load into recovery mode (which, depending on the phone, might need extra work)
- wipe some caches,
- select new os/rom image,
- pray it doesn’t brick your phone.
You’d think someone would’ve learned a thing or two from the easy graphical installations linux and even windows have been offering since the late 2000s.
The web-based installer for GrapheneOS is very easy to use. The catch is that it only works for Pixel phones (and only those that are still receiving updates).
https://grapheneos.org/install/web
I decided to install Graphene before looking up the installation and was blown away by how easy it is. I’d been on stock android for years and was expecting a similar experience as OP describes. My very old custom ROM folder is filled with files with names like ‘confirmedsafeblob’ and ‘bricksafe’ that I don’t even know what they are anymore but speak to some past misery. Then beep-boop done with the web installer.