Here is my version of how to do it from a non-programmer viewpoint and with help from my theme developer:
Transformer theme (PS 1.6 version)
How to edit the text and how to move the "spend another $xx.xx to get free shipping" to go under the cart total:
/public_html/modules/gmgetfreeshipping/views/templates/hook
Back up and then edit gmgetfreeshipping.tpl as you wish.
I changed it to show: Spend $xx.xx more for Free Shipping!
The text was originally left-justified (all the to the left) so for the Transformer theme, Jonny Li said:
Do these two steps:
Put this code to the "Custom CSS Code" field
HOOKSHOPPINGCART .blockgetfree_shipping{text-align:right;}
Go to BO > Modules > Positions > page, change the sort order of modules in the "displayShoppingCartFooter" section to move that text above.
In other words: slide the whole "get free shipping" module up in the positions for displayShoppingCartFooter (using the arrows did not work for me).