Instructions for a single-section kiln:
1) Unplug the kiln, vacuum the interior, and remove the lid. Turn the kiln upside down onto a protective piece of cardboard. Loosen the bottom of the stainless case.
2) Remove the screws holding the galvanized sheet metal base. Pry out the steel base with a screwdriver.
3) Lift out the kiln bottom and bottom row of bricks. Replace the bricks. It may be possible to salvage the brick bottom by flipping it over and using the other side. Reinstall the steel base.
4) Tighten the stainless case and turn the kiln right side up.
5) Install the new bottom element.