I have a Cannodale, but I'll take a stab at clarifying.
By "short tubes" do you metal cylinders about the size of very large finger? These are Co2 cartridges. I use an air pump, so I can't help out. I would go back to the shop and make them show you how to change a flat with tools you have.
Some links that may help:
http://parktool.com/repair/readhowto.asp?id=100
and:
http://www.sheldonbrown.com/flats.html