On OpenVix image, you can remove old EPG data by doing the following:
Menu / Setup / System / EPG / Load-Save-Delete / Delete EPG
For some people this does not work, especially if they have mount issues. This plugin/script is to stop Enigma2, find all instances of EPG.dat and Crossepg folder and delete it/them. Thanks to Birdman for the assistance
You will have to configure CrossEPG downloader again.
***DO NOT OPERATE WHEN RECORDINGS ARE TAKING PLACE***
Please uninstall after using it to prevent accidental operation. Ideally I would have liked to add a prompt before executing.
There is a plugin called system tools which does similar thing but not as thoroughly.