Have you ever associated an application with a file type, and wanted to change that choice? For example, when working with an acrobat form, I accidentally answered "Yes" once to Acrobat's question "Do you want to open all files of this type with Acrobat?"

After finishing that project I wanted to return to using Preview, because it takes way too long for Acrobat to open, but it's not at all obvious how to change the setting.

Select a file of the type you wish to reassociate, choose "Get Info" from the "File" menu. Under "Open with:" select the application you wish to use. Under "Use this application to open all documents like this. " click the button marked "Change All".

And that's all there is to it.