I was distro hopping for awhile in the past few months, so in order to keep all of my files secure, I made a partition of around 50 GB named Files to store all of my files in, and still have them for quick and easy access. However, now that I've found a distribution I'm comfortable with (Kubuntu 11.10), I would like to remove this partition, and have all of my files in my /home folder, in order to more easily deal with these files.

I've moved all of my files in the partition to my /home folder (and still have plenty of room to spare), and now I'm trying to delete the partition and use the space for my /home folder. I can delete the partition just fine, however, I can't extend the /home folder into the unallocated space. Here's a screenshot of what I'm talking about.

In order to change the size of the /home partition, I need to unmount it. But, I am unable to unmount it! How do I best extend the size of the partition?