If you mean for your main XF installation, it can be installed in the root or a directory, it makes no difference to the add-on.
If you want the home page to be the root domain though, XF should be installed in the root.
As far as installing the add-on is concerned, you just upload the contents of the upload folder (the same as with most other add-ons) and then import the xml file.
If you want the home page to be the root domain though, XF should be installed in the root.
As far as installing the add-on is concerned, you just upload the contents of the upload folder (the same as with most other add-ons) and then import the xml file.