in Virtuemart, if you go to check out in the backend, you have got four options, each with a tick on the left. On mine, you are able to undertake the first two ticks, the third and fourth are grayed out and you can't untick them. however, there are four boxes with one to four, these are the stages. If you just put zero in the ones you don't want to use (on the ones that are grayed out) it seems to work