If you do not have the correct size wrench the valve extenders if they are tufo as well will come with the tool to remove the valve core(cheap small black plastic thing). One size is for the valve core the other is for the extender. If you have neither I would suggest going to the hardware store to find the correct wrench sizes (the valve core and the extender may be two different sizes), just do not use a pair of pliers unless you absolutely have to, you can crush the valve super easy. I would also personally not suggest putting the sealant in until you flat, others will definitely disagree, to each their own. My reasoning is that the sealant is air activated and it is exposed to air in the tire and will partially gum up, which will make it into your valve core sooner or later, and you really do not want it there. Do not get mad if you already know this, but loosen to the left or counter-clockwise. I have raced and trained both tubulars and clinchers and I still like these best.

This link is about as good as I can find for at least the layout of valve and extender.

http://www.tufo.com/...;mn=7&co=prislus


and mounting

http://www.tufo.com/...;co=instrukce#Instr4