Write the next sentence in this paragraph:

How to build a single tank biodiesel processor
Gather together the few common items listed under " things you'll need.
"
Assemble the drum.
Cut a large opening (about half the top) in the top of the steel drum.

Options are:
(1). Leave sides open to conceal the motor's slot. Draw the bottom of the drum apart, allowing enough room for the motor.
(2). Cut the other two open at a 45 degree angle. Use a painted metal wheel or hole puncher to drill a hole between these holes.
(3). Push a two inch (5.08 cm) hose through the opening and remove everything else. Grind the urethane paste into your steel drum.
(4). You may also be able to find a drum with the top already removed. Drill a 1.5-inch hole in the bottom of the drum.
(4).