you first need to add a new profile in your game Risk of Rain 2, or replace your current one then close the game
next go to Steam/userdata/YOUR_ID/632360/remote/UserProfiles and paste the new_save.xml file
if you have multiple profiles there will be multiple .xml files, opening each one in a text editor and using Ctrl + F to locate the name can identfy each
finally, the file you want to replace, copy the name of it and paste it as the name for new_save.xml
relaunching the game should update it, then make sure you are using the new profile, and it should be working

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