How to fit a new door mirror glass on Vauxhall Corsa 2011?

Hi,

My girlfriend's passenger side door mirror got booted by some kids yesterday and they've smashed the glass (rest of the mirror, housing, etc. seems ok). I've bought a new glass so was wondering how do I fit it? Is it simply remove the cracked glass from the mirror assembly and put the new one in or do I need to take it apart to replace?

Cheers,

John
November 2012