Sure. The idea is that you work the decreases at the armhole edge in the same way as for the back, whatever that decrease is. For the center opening, mark off the center 10 sts and when you get to the marker for the 10 center sts, drop the strand of yarn that you've been using, pick up a new end of yarn and work 2sts, bind off by lifting one over the other as usual for a bind off and continue to bind off until 10sts total have been bound off. Continue to the end of the row with this second strand of yarn. Now you have two separate sides of the sweater each with its own ball of yarn. Turn to the back side and work across to the bound off center sts, drop the working strand of yarn, pick up the original strand and work across that first side. Continue working each side separately, doing the decreases at the armhole edges and at the neck edgea at the same time. It may help to write out the rows, marking the armhole or neck decreases on paper and checking them off as you go.