To add on to what Highbeam said, draining one of the rear lowers first, will reduce the amount of initial flow (unless you want to put your hand into the outflow stream to replug the big sump before your drain pan overflows) and reduce the chance of your having a drain pan overflow. Even when draining the rear first, you need a big drain pan. I think mine is 5 gal, and it gets as full as I like it for purposes of pouring the oil back into a 5 gal waste oil pail.