To begin, you need to unscrew the screws on the bottom of the shell.  Now, flip it over, and poke a hole through the middle of the round sticker on each side.  Stick your screwdriver through this and unscrew the screws in each of them.  (you may not have actually applied the stickers here; don't worry about it.)  Now unscrew the last ones on the top of the black handle, and pull the black halves apart (the actual sheild part of the shell should be set aside.)  Take a look inside, and remember where everything goes.  Now, pull out each of the plungers and stretch out the spring on each of them.  PUt them back in, and put everything back where it goes.  Screw it all back together.  Now, take a crayola barrel, and wrap the thinnest end with duct tape to a thickness that is quite tight in one of the barrels on the Manta Ray.  Only wrap around the thinnner area.  Once the thinner end is wrpped, take some of your electrical tape and wrap the unwrapped end to the same relative thickness as the duct taped end.  This makes your crayola barrels blend in with the black plastic, and also helps complete the seal.  Now, take the wrapped crayola barrel, and shove it as far up the manta Ray's barrel.  Jam it up there really good.  Do this with all four crayola barrels, for all four Manta Ray barrels.  Now, take your handsaw and cut two 1/2-cm or so slits down the end of each of the plungers, and then cut out this tab between the two slits to make a small notch in the end of each of the plungers.  Take your heavy duty rubber bands and loop them through the notches on either plunger, and stretch them around the backside of the Manta Ray's shell.  You may need to link a few of them together if you don't have as massive of rubber bands as I did when I did this.  That's it.  Here's a view of the finished Manta Ray, from the barrel end and from the top of your newly moified Manta Ray.  It should shoot stefan micros, and stock micros with ease.