How can I rollback an app from F-droid without loosing settings?

My question follows the discussion under link How to get an older version of an app from F-Droid? but the moderator unfortunately does not allow to ask for additional details in the same thread. So my question is the following: I have installed a newer version of an app in F-droid to find out it becomes unusable because of bugs. Naturally I want to revert to the previous version. I pertinently know the older version can be seen in the versions section at the bottom. But I cannot install any of them unless I uninstall the current version of the app. This unfortunately results in loosing all settings. How can I rollback an app from F-droid without loosing settings?