Yesterday evening I devoted some time to organizing my feeds in Google Reader. I wanted to add new subscriptions, remove some others and rename folders for a better workflow. And then I realized that Google Reader doesn't have an easy way to rename folders: no "Rename" button, no option in Reader's settings, nothing. I was about to start creating new folders and moving all my feeds to them, when I came up with this little trick to rename folders in Google Reader without having to turn all your feeds upside down.
1. Enter Google Reader's Settings and click on the Subscriptions tab.
2. Enter the folder name you want to edit in the filter text field on the right side.
3. You'll see a list with all the feeds saved in that folder. Now click on the "Select all" option on top of the list, and right after that create a new folder with the new name on any of those feeds, by clicking on the "Change folders" button and selecting "New folder".
4. Go to the "More actions" menu and select the new folder you just created under "Add tag". The tag will be applied to all the selected feeds.
5. Now, in that same menu, select the old folder name under "Remove tag" and voilà! All the selected feeds will be saved now under the new name.
6. The only thing left is going to the Tags tab and deleting the old folder.