Originally posted by Dale Cooper:

Ok, i tried to rename the plugins folder but when i enter in a new world but the game crashes.
Same thing when i rename the "doorstop_config.ini" to .bak or other else extensions

if I install a modmanager now will it be able to import the mods already installed?

If you use a mod manager you're limited to only the mods for that platform (as far as I know)
Nexus Mods with Vortex or Thunderstore.io with Thunderstore mod manager. Thats the down side.
The upside is, at least with Thunderstore MM, it allows you choose how you launch the game. Modded or Vanilla, which should also keep the launching from steam Vanilla too.

If you're looking to "vanillafy" your install to remove all mods the following image is the unmodified folders and contents of whatever you named your Valheim installation folder, "Valheim" by default. https://prnt.sc/S6HP7rtZu0Y5 Also verify your steam installation as well to make sure none of the mods changed any of the files.

If you're looking to just disable your mods AND ALL the mods run off BepInEx, you can just rename the BepInEx folder. For example I just rename it to "Disabled BepInEx" and the mods no longer load. https://prnt.sc/4w_Lrj8AdEBj Highlighted files are the fresh install only files.