Very Simple, I just heard how Tom played it Live this Way:

Well I ^EmWon´t^D back^G down, No I ^EmWon´t^D Back^G down, You can ^Emstand me ^DUp at the ^CGates of Hell, But I ^EmWon´t^D back^G down.

I´m Gonna^Em Stand^D my^G Ground Em- D G Won´t be Turned around And I ^EmKeep This ^DWorld from ^CDraggin´ me Down Gonna ^EmStand ^Dmy ^GGround And i ^EmWon´t^D back^G down

Refrain: C D

^CHey, ^DBaby,^G ^D ^CThere Ain´t No Easy Way^D Out ^CHey, ^DI, Will ^EmStand ^Dmy ^GGround, and I ^EmWon´t^D back^G Down.

Well I Know Whats Right, I Got Just One Life, In A World That Keeps on Pushing Me Around, But I Stand my Ground, And I Won´t Back Down Repeat Refrain 2x Listen, Folks, Thats not Just a Song, It´s a Prayer! Keep Rockin!

Tom Petty - I wont back down