W.I.P.
Update 18-09-2022: Below should work for v1.2 too.
Update 30-07-2022:
For updating to version 1.1, download the new v1.1 .zip. Once you've imported it into MMC/PMC, optionally copy over from the version 1.0 instance:
%MC Instance% 	- local (folder)
				- screenshots (folder)
				- options.txt
                - options.justenoughkeys.txt
                - options.amecsapi.txt
                - config/roughlyenoughitems/config.json5
... To keep your current keybind settings, screenshots, explored map/waypoints and REI bookmarks.

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Update 26-07-2022:
Replace the old enchantment_config.json5 with the new file in %MC Instance%/config/fabricenchantments/

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MultiMC:
https://github.com/MultiMC/MultiMC5/releases
Go to Settings -> MultiMC -> Update Channel -> Select Development -> Restart MMC.
You can add an instance downloading the modpack and using "Add Instance" -> "Import from zip". It may take a while to import.

Java downloads: <You need Java 17>
https://adoptium.net/temurin/releases -- Hotspot
https://github.com/graalvm/graalvm-ce-builds/releases -- GraalVM
OpenJ9 -- GL finding it pre-built now. If you do, let me know.