getting rust out of my gas tank?

[ava83/52]

looking for some pointers on how to get rust out of my tank? the out side of the tank is like new and has no leaks. dont want to buy a new one if i can clean this one up.

 

[roy 1955 chevy]

hi member im new here but i hope you got your gas tank cleain i used rocks in mine or a dog chine work to . and shake away .