You just click on it in your magic menu (or even favourite it so it is in your 'Q' menu) then press Z and it will activate. Sometimes though bosses or higher level creatures/enemies will not be affected by it.
Antec 902 | Intel i7 920 2.66Ghz OC'd to 3.40GHz | MSI GeForce GTX 660 Black Knight 2048MB GDDR5 | Corsair 6GB DDR3 | Coolermaster V8 CPU Cooler | W7 64
"There is only one way to avoid criticism: do nothing, say nothing and be nothing." Aristotle
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