I think liam was spot on - dont think you have to change you play just coz its a big event - have confidence in your abilities ( at the end of the day it got you there in the first place!!)
I am not experienced in this type of event however I think table perception is very important, so try if possible to win early with clean/solid play, it allows you to open up more in later stages.... if you hit lucky early on through bad play your ability to gain respect when you need to push, steal, bluff is restricted..
Take time to watch your table - larger events are marathons not sprints, you will find your oppertunities just make sure you have enough of a stack to maximise them..
Final point - if you get short stacked stick to abc poker - dont put yourself in a position where you go out regreting the play...hard i know but ultimatly finishing an event ( in what ever position) an knowing that you made the right play is important for you to carry that forward to next ...
Good Luck