split up checkout process in several pages (Steps)

I am curious what the best way is to split up the checkout process in several pages. Currently all the data is displayed on one single page but I want to have a separate page for Order Overview, Address, Payment Options and Order Complete page. A next button is also necessary at the bottom of the page which might complicate some matters.

Obviously this requires php modifications, but I am wondering what the best approach would be.

Thanks!

BTW running on old 1.6 here -.- will look into having the company upgrade sometime in the future

EDIT:
Lol i'm stupid and blind.. this is already built in <3