Remove Linux-libre

Trisquel's default kernel is not Ubuntu's. To get back to Trisquel's default kernel, make sure that the package "linux-image-generic" is installed (and install it if not) and remove the newer kernels. You can then remove the repository with the newer kernels, if you wish. After a reboot, you should run Trisquel's default kernel. Running the following command in the terminal would confirm the version:
$ uname -r

Trisquel's default kernel is not Ubuntu's.

Kindly pointing out that I'm running Ubuntu, as per my original post.

I ended up reinstalling Ubuntu. Still, I'd like to know how Linux-libre may be uninstalled in order to revert to Ubuntu's default kernel. The FSFLA gives accessible instructions on how to use Linux-libre but no method on how to remove it.