Does anyone know how to remove the valve stem on the DB30 rims? I had a heck of a time getting the tires off the wheel, and really hated the 10 LBS of green slime the previous owner had in the tires. I did some research and it looks like if you remove it you should install a new one. Do the DB30 take a standard size valve stem and is a special tool required to remove the old and install a new one.