With this release, we have just updated the version of the product 2.x to allow upgrading from 1.x version to 2.x without losing usergroup permission settings.
Simply upload the files form this package and you can find the add-on under upgradable XenForo 1.x add-ons. Running the update will enable the add-on and will keep usergroup permissions you had setup in XenForo 1.x