Super Mario Brothers 1-UP Green Mushroom? Check.
Too much other, more important **** to do? Check.
Useless drill with bad batteries? Check.
Falling victim to my OCD and doing this pointless and awesome mod anyway? Check.
1. Drill 12mm hole in bottom of mushroom.
2. Thread 12mm nut onto threaded end of shifter, followed by a 1" wide, 12mm washer, followed by the mushroom can, another washer, and another nut.
3. Tighten your nuts.
4. Cram your can with heavy brass balls or whatever gives your stick some weight.
5. Slather the inside of your mushroom helmet with Mighty Putty, and jam it on the shifter.
6. Wait a day for the glue to set, and crustify.
7. Grab your new mushroom tip and ride. And be safe out there, kiddies.
Ahh, now I can go to sleep tonight.