You can install it on a stock ROM after you install Titan. Find the titan link in Start Programs > Titan. Find the link for and download the CAB. Install the CAB only when you are not connected to a PC with USB and not using WiFi. Reboot.

Fire up opera mobile, visit mini.opera.com, download. Titan's content manager will walk you through installing and launching it. You will find mini in Start > Programs > Content manager.