When you start up your machine, you'll see both drives are recognized by the mini.

Xbench scores show that if you install hard drives in either the top or the bottom position, their speeds will remain the same.

To minimize the amount of work necessary when adding an SSD to be used as your primary drive, we recommend installing the SSD like we did in this guide and leaving the stock platter drive in its original bottom position (closest to the antenna plate).

After reassembly, boot the mini into Lion Recovery and use disk utility to erase your SSD. Then install Lion on your SSD. After rebooting, go into system preferences>startup disk and choose your SSD as the startup disk.