unless there are 2.1 implementation breaking changes:
download the file
unpack
go info.json
set factorio version and base version to 2.1
update mod version to your liking
save and repack the directory similar to original zip file
push to %appdata%/factorio/mods
be aware this hides official version update. you can simply delete local mod file and repull the file through ingame mod manager.
i am currently testing my own fix and will upload a 2.1 fork until official is ready.