If you’ve downloaded a modpack but don’t want to use all the included mods or if you’d like to add new content you can customize your experience by modifying the modpack’s contents.
How to Customize a Modpack
From the My Modpacks tab, click on the modpack you want to customize.
Open the context menu (three dots) and select Profile Options.
Check the box for Allow content management for this profile and click Done.
An Add More Content button will now appear. Use it to search for and install new mods, resource packs, or maps.
You can also manage your installed mods directly by toggling them on or off from the Installed Mods section.
Important Notes
Only mods that match the same game version and mod loader type of the modpack can be installed.
While Allow content management for this profile is enabled, the modpack cannot be updated or changed to another version.
If you later disable content management, any custom changes you made will be overwritten when the modpack is updated unless you choose the option to update into a new profile.
Modpack version updates are disabled when content management is active.