Data Pruning
Control Panel Location: Admin > Utilities > Data Pruning
This section of the Control Panel allows you to "prune" or remove old weblog entries, comments, forum posts, etc. based on various criteria. Each page will present you with various pruning options.

Be careful using this feature as it will permanently remove the data from your database. You are encouraged to Backup your database before using this feature.
User Contributed Notes
You must have an ExpressionEngine license and have attained a forum rank of "Lab Assistant" (100 posts) to contribute notes to the User Guide