about 2 years ago - Irongate Smiffe - Direct link
We have a guide on discord.

If I use mods, will I be able to play when the game updates?
Every time we update the game, many mods that players use become incompatible with the game. Until your mods have been updated by the creators they will most likely not work with Valheim. To make sure you don’t lose anything, it’s a good idea to backup your worlds and characters [C:\Users\ \AppData\LocalLow\IronGate\Valheim] where mods are used before downloading new updates. In order to be certain that you can play larger updates right away, you should also have your mods (temporarily) removed.

How do I disable most mods so I can play the latest version of the game?
Go to steamapps\common\Valheim and move, delete or rename doorstop_config.ini file

How to completely delete most mods?
Go to the above folder and delete all folders EXCEPT [MonoBleedingEdge] and [Valheim_Data]
And also delete all files EXCEPT steam_appid, UnityCrashHandler64, UnityPlayer, Valheim