Assuming you mean the first step at the top of the stairs what you will have to do is lay your flooring as normal up to the edge of the step and then buy an 'L' shaped trim which will screw down onto the laminate and cover the join between the stair riser and the floor.You can buy trim specifically for this purpose and it should be grooved for extra tread but make sure it is fixed securely with the correct size screws because a loose trim could be very dangerous.