Use a white marker and a square(speed--the triangle one) to draw lines on all four sides. Then use a hand saw to start kerfs on all four sides(prevent splintering) and finish the cut.

A small saw like a dovetail saw(has a rigid bar on the top edge) or a pull saw would be the best.

A speed square won't work.....those are tapered posts

Use a short level to carry a level line around all four sides of each post making sure they align.....

I'd clamp two boards on opposite sides of the post....positioned just below the pencil line......to guide a handsaw

Move the TV?
:-)

Sorry, couldn't resist. Good luck - with these two pieces of advice combined - clamp boards on to guide the saw, and pre-cut all sides to prevent splintering, you should get good results. Hope those rails across the top don't have a structural role!

KarinL

The speed square will work by marking the corners and using the straightedge of the square to make the straight lines.

The level will also work. Buying a plastic speed square is usually less expensive and has more DIY uses than a level.

sell this bed and buy the one without posts?

I would have to agree with the speed square NOT working?? These are tapered posts. The speed square will cause an angled downward line, at least mine would! Maybe they make one that isn't 90 degrees. I guess an adjustable square and a level would work...

Use a try square or speed square or machinist's square and measure each side from all four possible positions. Each facet of the tapered post will then have a diamond on its face. Connect the dots and make the cut. (If you use a guide it will throw your cut off unless you compensate for the taper again by chamfering the edge to match the taper of the post.)

OR: make a jig by ripping a length of clear 1" stock so that a piece that's clamped to the post is flat on top. Make a tapered flat-top box that's open on both ends and drop it over a post snuggly. Make the cut or the marks and move it to the next post and so on. Might not be worth the trouble for just four posts.

Good luck,

M