How to recursively change sharing/permission of a folder in Mac OS X
Solution 1:
Try the chmod command. For example, if you have a directory name mydir, the following command will enable read/write for that mydir recursively.
$ chmod -R +rw mydir
For more information:
$ man chmod
Solution 2:
Select the root folder that you'd like to work with and open the Inspector (CMD-i or right click and "Show Info"). The bottom panel is where you can manage permissions.
Add and remove permissions to the list there. To apply the same permissions recursively to every subfolder, click the cog and select "Apply to Enclosed Items..."
Note: I noticed that the "Apply to Enclosed Items..." is greyed out when the little lock icon at bottom right hand side of window is locked. If this is the case just click on the lock to unlock it by entering your credentials and then try again with "Apply to Enclosed Items..."