I think you have to have the java thing, the lastest flash player and then you have to follow the steps.
You don't - you buy it.
google, plants vs. zombie
You can download plants vs zombies 2 for FREE at HUBPAGES.COM.
To get the password of Plants Vs. Zombie you need visit a number of forums to get the various codes.
May be you can download the free version. Wel see the related links below as an example.
The Yeti Zombie
Yes you can
Popcap.
you can download plants vs zombies at gamehouse
what is the password of plant vs zombie
The Smallest Zombie is The Imp i think
about 1 min not long