The Huawei Mate 8 is part of a dying breed: phones with micro SD card slots. You can add a possible 128GB of extra storage with a micro SD card. The process is very simple.
First, use a SIM removal tool or paper clip to push into the small hole on the left side of the phone to open the SIM card tray. When the SIM card tray pop out, pull it all the way out with your fingers.
Place the micro SD card in the tray as pictured below.
Slide the tray back into the phone. That's it! You now have more storage in your Mate 8.
Note: you will not be able to use dual SIM cards with a micro SD card.
First, use a SIM removal tool or paper clip to push into the small hole on the left side of the phone to open the SIM card tray. When the SIM card tray pop out, pull it all the way out with your fingers.
Place the micro SD card in the tray as pictured below.
Slide the tray back into the phone. That's it! You now have more storage in your Mate 8.
Note: you will not be able to use dual SIM cards with a micro SD card.