The Content Versions action, available as of Smartsite 7.10, lets you manage the content versions.
It gives an overview of the number of versions there are:
Select which type of versions you want to purge and select a time period / date to only purge content versions which are older than the select period / date.
When you click the Remove button, a confirmation dialog will be shown first, informing you how many content versions will be purged.
The Items tab shows the top 20 of Content items having the most content versions.
As of Smartsite 7.10, the Item Details has undergone several changes too.
The content versions and status changes has been combined into a single overview, showing the top 10 most recent content versions and the related status changes.
The button Show versions will open a library, showing all content versions and status changes for this item.
Furthermore, when the user has access to the action with code "mgr-CONTENTVERSIONS_SINGLEITEM", a button will be available on the bottom of that list which will open this (manage) Content Versions action for a single item.
There's also an option available to remove the content versions of child items as well, using the same settings.