Upgrade your Xperia™ X10 mini and Xperia™ X10 mini pro to Android 2.1

This tutorial teaches you how to upgrade your Sony Ericsson X10 mini or X10 mini pro from Android 1.6 to Android 2.1. Begin by downloading the latest version of the PC Companion on the Sony Ericsson support page. Choose the correct model and downloads and find pc companion to install it on your computer. Next, connect the phone to the computer using the USB cable. Then select PC Companion on your phone and the phone will tell you there's a new version available and to click to update.
Next, you have to download the latest version of backup and restore on the Sony website. On your phone's status bar, tap on "Turn off USB storage" and then "Turn off". Disconnect the USB cable from the phone. Follow instructions on the phone to back up your data. Reconnect the phone to the computer, tap "Connect your phone" and follow the on screen instructions to update the phone to the newer Android version.