How to Delete Multiple Friends on Facebook.Now Lets do it wit help of some Scripts

Software Requirements
FireFox 4 or later
Download
Grease Monkey Add On
Download
Start:
First Install FireFox
Then Download Grease Monkey Add On
Install add on and Restart Firefox
Then Grease Monkey Icon will be visible on firefox(If itz not active click icon)

Go to the download page(Click Install Script) and install the script
Install Script ( userscripts.org/scripts/show/43404 )

Now a new popup window will ask you to Install Script
Click Install

Installation Ends Here!
Begin Deletion Now!
Go to ur Facebook Profile -> Friends
Wait till script loads
Hover over one of ur friends name(Where Unfrend Really Comes)
Then Refresh the page
Now you will see Check Boxes aginst friends as seen bellow
Select the friends u want to Unfriend

Click on the Arrow Button

Select Highlight Only Button
Now it will begin Deletion

Click here to get Greasemonkey add on

FacebookDeletes for Greasemonkey