Begin the process by removing the baseboard trim (figure A) from the walls where the wood staples will be attached. The headboard and sideboard of the bed should be flush with the wall. Remove the trim with a pry bar, saw, and chisel.
Measure from the wall panel and mark the location of the wall clips. Staple placement closest to the panel should allow a 3/4" gap between the staple and the edge of the panel. The gap will allow room for the decorative stud to be added later. Attach the staples to the wall with adhesive. building and finishing nails Repeat steps on opposite end of bed.
With the staples installed, put the head unit in place and secure it to the staples (Image 1). Molding can be added in the corner where the bed meets the panel (Image 2). Install trim with finishing nails for a clean, decorative finish. Attach the toeboard section to the staples at the opposite end by nailing the toes with finish nails. With the headboard and footboard in place, position the center panel (Image 3) and attach directly to the wall using finishing nails.
Attach the first bottom rail to the center panel and use a carpenter's level to make sure it's perfectly level. Use wood shims to hold the side rail in position and level, and attach the side rail to the bed frame with a surface mounted bed rail bracket (Image 1). Attach bracket to frame and rail with wood screws. Repeat the process for the second (outer) bottom rail, taking into account the width of the bed slats (Image 2). Repeat the steps for installing the two rails for the top bunk (Image 3).
With all fixed components in place, the trundle can be installed under the bottom bunk. Add the plywood supports and install the mattresses on the top and bottom bunks.
Finally, install the ladder at the foot of the bunks. The finished bunk beds, with the removable trundle, offer flexibility. The side rails are removable in case you want to convert back to a single bed.