To open cover of HTC One, disconnect from your smartphone and all of its peripherals (USB Host, computer, charger, headphones, etc.). Unlock the screen and then click on the power button and hold it for a long time. A menu will appear. Select "turn Off phone" or similar (depending on firmware version). Don't confuse it with "Restart". A new menu will appear. Select "Yes", "Off" or similar. Wait until the machine is completely turned off.
Turn the phone screen to itself, the USB connector down and the headphone Jack and power button up. On the left wall you'll find a lever. Pull it towards the top of the wall at which are located the headphone Jack and the power button. Back cover razblokirovat, and you will be able to remove it.
The battery of the smartphone fixed, so its under cover you will not find. Therefore, make sure that the power button is accidentally pressed with the cover removed, as in an enabled state to change the SIM card and the memory card is undesirable. But in the compartment will be two slots for SIM cards and one slot for a Micro SD card. In a variant of the HTC One, designed for one SIM card and not having the lid, inserting a memory card is not provided.
Installing the SIM card correctly select which one in which slot to install. One of them (top) allows you to use 3G and the other doesn't. On the map you want to use to access the Internet, must be connected unlimited plan, and she needs to be in the home region. The Micro SD card can be up to 64 gigabytes.
Installing the SIM card and memory card, replace the cover back. Turn on the device by long pressing the power button. Wait for the operating system Android. If necessary, reconnect the peripheral devices. Continue using the phone.