There is a reason that the file says 'Do not edit'. By messing with it you can create monsters like the two threads below which are basically unremovable. I can do it, but I'll need to remove every post that you have made to the forum. Not a solution that I'm up for.
Do not edit the cookies that you receive from the forum. There is no valid reson to do so. I can however think of many invalid ones. Please leave them be.
I took a look at the problem posts and was able to remove them. pH34R |\/|y 1337 $kI11Z!
As for editing cookies, it's doable, but why would you want to? If you don't know exactly what you're doing, you'll just ruin the cookie, causing smallish problems left and right. So why bother?