How do you sand this to take a stain

Hello. Our Stainable Wood Filler accepts stain, though sometimes at a different rate from the surrounding wood. This is often due to the natural porosity, age, or moisture content of the wood. Please try these suggestions, based on lab tests for the Minwax Stainable Wood Filler, to get a closer match to the surrounding stained wood: 1.) Lightly sand filler before applying stain (no finer than 100 grit.) Over-sanding or using a finer grit tends to close pores. 2.) Stain as soon a possible after filler hardens, following label instructions for the stain. The longer the filler cures, the harder and less porous it will be, and therefore the less stain it will absorb. 3.) If the first coat of stain is not as dark as desired, in a sample area use a piece of 100-grit sandpaper and dampen the sandpaper with the stain you are using. Use this paper to wet sand the Stainable Wood Filler. I would recommend rubbing out the area with light pressure in the same direction as the wood grain. Increase your rubbing/sanding pressure as needed. You should notice that the combination of the stain and sandpaper is blending the Wood Filler compound with the surrounding stained wood. Here again, practice your technique in a test area or inconspicuous spot. Regards, Minwax Customer Support