Is there any way to put it into tires that are already mounted without removing the valve stem or core?

Removing the core is easy. It just unscrews. They make a special tool which is like $2, I just use a very thin set on needle nose pliers. It takes seconds to take out. Jack up the tire, remove the core and let all the air out.

It install the equal, I got some tubing that fits around the valve stem, attached the other end to a plastic funnel and pour it in.

If you're gonna be at Whispering pines, you think you could help me out with this there?

try here, they list 3 places in rochester that are distributors:

http://www.imiproducts.com/distributor-locator/results.aspx?state=NY

Edit to Add: There are actually 4 addresses, the fourth being on the second page.

Thanks Erik, i'll give them a shout next week.