Install an array controller on a installed server

Hi all,

I have a HP ProLiant ML350 R04p 3.4GHz Xeon with Windows server 2003
installed on it in a mirror as it didn't come with an array
controller.
Now I've bought a Smart Array 641 controller and I was wondering what
the best way to install it (shortest time).

Do I break the mirror, install the array controller and set the array
on the 2 disks?
Won't i loose all the information on both of the disks?

Thanks for letting me know,

Sofie