I had already made the dough into a pizza and while waiting to put it together it has risen. What should I do?
It does that if it gets the chance. You can either roll it thinner again or (my preference) have a slightly thicker, fluffier pizza,which may take a minute or two longer to cook. If you knock it down with your knuckles after rolling it tends to spring most of the way back.
This, by the way, is almost inevitable if you cook pizza with children as they slow down all the prep. If you really want a very thin crispy pizza you have to work rather fast once it's rolled out (and use a very hot oven so the yeast is killed as soon as it goes in).