You don't need a low angle block plane (#60 1/2 in this case), but it is the best plane for the job IMHO. Make sure it's nice a sharp, as end grain likes sharp blades.

Skew the angle so it's attacking the piece at an angle. This will help avoid tear out. Alternatively you can start at the far edge and take a couple passes then move back to the close edge, essentially working towards the middle. As long as you have a sharp plane and you're skewed, you don't need to though.

Take passes at the angle you desire until you reach the depth you want. Since this is for a bench base that will be dragged around on the floor, the chamfer is really just so that the end grain doesn't catch and tear out when moving across the floor. To keep a consistent angle, you can put your fingers on the sole of the plane on both sides of the piece to use as a "guide".

Nice chamfers all the way around.