waiting for an anwers too :)

If you got a yaml file (or bit of text) click the modlist button, and select import. Alternatively, you can load the list from a save game file.

Open up rimworld then go to options.

click on save data folder

That will open up the folder you need. Now you should see a folder that says "ModLists".

Drop your xml file into that folder and restart rimworld.

When the game loads back up again click the mods button. Then in the middle bottom of the screen you should see a save icon. Click the save icon and you should see the saved mod list right at the bottom. Click the correct saved mod list you wanted and there you go.