With your goggles and mask on, use the multipurpose bit and the router attachment to slowly cut out the outline. It’s generally best to start with the deepest parts first. Decide on your deepest depth, and adjust the router accordingly (3/4″ is generally as deep as you want to go). Cut on the inside of your lines (unless they’re letters).
After you cut out the outline, carve out the rest of the area using the large cylindrical drum sander bit. Go slowly, or the plastic will melt, flinging melted plastic at you and ruining your bit. Do this to each area until your tombstone is carved out completely.
TIP: For depressed letters (easy), cut along the inside of the letters with the multi-purpose bit. Then, using the flat bit with the ridges or the chainsaw sharpening bit, adjust the depth and clean up the inside of the letters.
For raised letters (difficult), cut along the outside of the letters with the multipurpose bit. Carve out the letters and at least an area of 1/2″ surrounding the letters. Next, take the flat, ridged bit (or chainsaw bit) and clean up around the letters. Raised letters look nice, but they’re more difficult