The Analytics Database Manager (ADM) module can help you to purge historical data from the Sitecore Experience Database (xDB) and clean sessions that are older than a certain date. This lets a customer remove unnecessary data from xDB, in particular from collection databases. The tool is sufficiently flexible to purge data by a specific criterion or by a combination of criteria, and can even be customized to filter the data on customer-specific criteria.
Download the relevant module version and its accompanying document available on this page: KB0232559. Then install the module following the Administrator guide.
The module is provided as is, and is not covered by Sitecore Support. To report any bugs and requests for the module, send an email message to Sitecore.ADM@sitecore.com. All provided comments will be considered for later releases.