Jan, if you are using a Campagnolo chain, it is not advised to re-use a pin. You are better off using a Campy specific 10 speed quick link.

I have used my old park CT-3 chain breaker to shorten the chain to proper length, but have since bought the new CT-4.2 chain tool.
http://www.parktool.com/products/det...=5&item=CT-4.2

I know you don't have an aversion to picking up a new tool now and again.