How can I associate OpenOffice documents with OpenOffice apps instead of TextEdit? I just updated to Mountain Lion.

My documents were prepared in OpenOffice and contain many mathematical equations. After updating to Mountain Lion, the documents open in TextEdit instead of OpenOffice. This is an issue because TextEdit doesn't render the equations properly.

How can I re-associate OpenOffice documents with the OpenOffice apps instead of TextEdit?
Go to one of your OpenOffice documents in the Finder and Get Info (⌘+I). In the "Open with" section, choose the appropriate app in the popdown (OpenOffice or LibreOffice), then click the Change All... button and hit Continue in the confirmation dialog.