how to install
 

i cant figure out how to change the stuff in the templates, do i do this through the admin cp or do i change files and upload them, and how?

Template modification are done in the AdminCP-->Styles

do i do that in replacement variable manager?

ACP-->Styles & Templates-->Style Manager--> Click on <<>> behind the style you want to change and you will get a list of all templates in that style.

Now double click on the templates name to edit the source of that template.