the first thing i did was remove the stock filters and trace them onto a piece of disposable grill liner, then cut out 2 circles of mesh with a pair of wire cutters. once i made sure they were the right size i glued them inside of the caps/ lid to the mask with some gorrilla glue, the foam helped keep it in, just make sure you don't use to much or it get into the mesh and makes it look all messy. once that was done i went about making the led circuits i used 2 cr 2032 batterys + clips, 3 black light uv leds, 1 large blue led a double pull double throw switch with a center off position then i used some per circuit board. i also used uv paint on the grills of the mask, some red paint on the center vent hole to paint the molded in cross, then a handful of spikes and small accent pieces.
i made this for under $20 counting all the electronic components paint spikes and mask