Area Spells: Casting and Drain, And successes.... Options

[Paul]

Okay so break it down for me, oh legions of DSF, if a Mage casts a area effect spell on multiple targets how exactly does this work, from start to finish: In example Fred the Bear Shaman casts a force 6 Stun Ball spell (Fred has a rating 6 magic attribute, and a spell casting skill of rating 5.) on a an approaching group of corporate goons (They each have a Will power rating of 4; and they number 9-and have no spell defense dice allocated to them.) From casting to drain how does this work, step by step.

I have a reason for asking for it this way, and I want to see what other people say before I reveal it.