1. Press Escape
2. Click 'Log Out'
3. Select a max level, high CP magicka character
4. Click 'Play'
5. 'X' up in Guild Chat
6. ???
7. Loot

Warfire made a great stamina DD build for vAS+2 here
You should try to get a source of major evasion for the jumps/ St. Llothis' poison cone. Mirage is good if you're playing a stamBlade but Blade Cloak can also be used.
As the build suggests unless you are really comfortable knowing when Storm The Heavens is coming you should use shrouded daggers to damage the 3 bosses, which you can use at a safe range.
To help with both of these points I would use an Asylum Tracker so you can move away from St. Olms when Storm the Heavens is about to start and also appling your Major Evasion before the cone blast is going to start.

That being said I also recommend @BadShogun 's advise if at all possible.

For regular vet you just need a decent movement and for the last boss its good to have a formation and that every players know the mechanics, its not that hard. vet +1 or +2 is another story, i would suggest @BadShogun's tactic