Painting and Preparation
Lay down a sheet of plastic to protect the ground from paint splatters. Put saw horses or another means of keeping the boards from touching the ground over the plastic.
Paint both sides with a primer first and let them dry.
Paint the face side of the board the color chosen for the structure.
Stack the siding close to the work area to make it convenient to move when it is time to cut and install it.
Lay the siding flat so that it doesn't break.
Set up a cutting table. The table will consist of saw horses set up with 2-by-4s or planks set on top the length of the table. The table should be long enough to hold both sides of the siding up when it is cut. Use wood blocks to build up the table so that the board will be level with the miter box table when it is laying flat.
Nail the blocking about four feet apart down the whole length of the table. This will keep the hardie board from breaking mid-cut. This build up will also make it possible to use a jig saw when making small cuts.
Cutting the Siding
Cut straight cuts and straight angle cuts through the hardie siding using a miter box, which can be adjusted to the appropriate angles as needed.
For length cuts, use a circular saw outfitted with an abrasive blade rated for concrete cutting. Place the saw flat on cutting surface and adjust the circular saw depth table so that the blade only cuts through the hardie board.
Cut angles, holes and arches in the hardie siding using a jig saw. Jig saws outfitted with a masonry blade will be able to follow any lines that are marked on the hardie siding that a circular saw can not. Adjust the speed of the jig saw to a pace that allows the blade to cut the hardie siding without a lot of vibration.
Sand down the cut edges of the siding with sand paper and paint it before installing.