You can watch the first part of this video to learn how to replace the battery.
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You can watch the first part of [https://www.google.ro/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&cad=rja&uact=8&ved=0ahUKEwiBofaHzYnWAhXLBZoKHWv8Di4QtwIIYzAN&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DEA7wii8hsUE&usg=AFQjCNFBGtGuGCznb9TH7LRXZvdLG_lXIQ|this video] to learn how to replace the battery.