Where I ride it is legal for a bicyclist to ride hybrid mode. This means that I am legal to ride on the sidewalk, but I must move over for pedestrians. It is also legal for me to use the road, but I must act as a vehicle and obey traffic laws. I prefer the sidewalk, but the park I ride at requires me to cross 1 signaled crosswalk and 2 full blown intersections to get there from my house.
When I use the crosswalk I push the button and wait for the walk signal. I then dismount and walk the bike across. That is the only legal way to use the crosswalk that I know of. It is prohibited to ride the bike through even when it says walk.
If I were acting as a vehicle I would simply stay centered in my lane and wait for the light to turn green and then ride through the lane.