Inserting The Microsd Card; Replacing The Back Cover - HTC HD2 User Manual

Chapter 1 Getting Started 

Inserting the microSD card

The storage card slot is located at the lower left side, just below the
battery compartment.
Insert the microSD card into the slot with its gold contacts facing
down and push it in until it clicks into place.

Replacing the back cover

After the thin film has been removed, and the SIM card, battery, and
microSD card have all been inserted, put back the back cover.
Secure the right side of the back cover first and then press down
the cover into place.