editingRectForBounds: how to implement for UITextField

I am attempting to adjust the margin on a UITextField, and i have done a bit of research and found that i need to use editingRectForBounds: While that should be helpful to most people I find that I need a bit more guidance to make the nessesary cod开发者_开发知识库e changes. Could someone please point me in the direction of a tutorial or maybe write out just a quick couple steps how i might use editingRectForBounds: to adjust the UITextField text?

Ive seen this, but am not sure how to make it work.

Thanks for the help!