Samsung Galaxy S5 Quick Start Manual

Samsung Galaxy S5 - How to insert your sim card
With the back of the phone facing you, look along the left edge
of the device and near the top you will see a small gap. Gently
pull the back off of the handset using this gap.
The Samsung Galaxy takes a micro-SIM card that, although
smaller than a standard SIM card, a micro-SIM is inserted in to
the phone in much the same way. Before inserting the battery
and with the rear of the phone facing towards you, locate the
metal clip which sits beside the camera lens. This is the
housing for both the micro-SIM card and a microSD card (an
additional memory card if you are using one).
The micro-SIM fits into the lower slot, with the gold-coloured
contacts facing down and the cut-off corner going in first. This
should slide in until the edge of the micro-SIM is flush with the
edge of the battery well, as shown below (left image);
The microSD memory card (if you use one) slides into the
upper slot with the gold-coloured contacts downwards and
narrow end in first, as shown below (centre image);
The image on the right below shows both cards being loaded;