Is there any way I can copy/edit the cookies in Chrome Developer tools? Or do I need to install a custom add-on for this?
I think I have found something. I can press Ctrl+A and Drag & Drop the values in a TextBox and then copy it from there.
As pointed by @jmccure,
Ctrl+A, hold Shift and right click and copy.
Update: Chrome 58 added a support to edit cookies