How to jailbreak a iphone 4 verizon IOS 6.1.3?

I want to know step by step how to jailbreak a iphone 4 on IOS 6.1.3 if i can't jailbreak on IOS 6.1.3 how do you downgrade to IOS 6.1.2

Its complicated just follow the instructions here
http://www.greenpointstar.com/pages/full_story/push?blog-entry-Permanent+Unlock+For+iPhone+5-4S-4-3Gs+iOS+6-1-3+Unlock+AT-T-Verizon-Sprint-T-Mobile+and+More%20&id=22346178

Try talking or sending it into a jailbreaking service. Its far easier.here's a good one.https://www.facebook.com/official.drjailbreak

Download the latest Redsn0w Here (https://sites.google.com/a/iphone-dev.com/files/home/redsn0w_win_0.9.15b3.zip?attredirects=0) and follow the instructions Here(http://www.ipho9.com/how-to-jailbreak-ios-6-1-3-iphone-4-3gs-and-ipod-touch-using-redsn0w-download-links/) you will also need an ipsw from here (http://www.felixbruns.de/iPod/firmware/)