After installing a package from a PPA if you find you don't like using the testing packages or something broke and you need to revert the changes, you can use ppa-purge to revert those changes. It's possible to do things manually but usually that's for more experienced testers. Ironically, the ppa-purge package itself is available on a PPA. How strange is that?
Note: Newer Ubuntu releases has ppa-purge in the repositories. If you're using a recent Ubuntu version, try installing ppa-purge using apt-get first. You may not need to go through all the extra hassle.
Download the deb package for ppa-purge from X-edgers PPA and install it.
~$ cd Downloads/
~/Downloads$ sudo dpkg -i ppa-purge_0.2.6_all.deb
Then remove a ppa package with,
~$ sudo ppa-purge ppa-url
Replace ppa-url with the same line you used to add a PPA to software sources and ppa-purge will take care of the rest.
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