What is the fine-grained topic of the following text: These instructions will hopefully assist you to start with a stock ZTE AT&T Trek 2 HD, unlock the bootloader (if necessary), and then download the required tools as well as the very latest source code for LineageOS (based on Google’s Android operating system) for your device. Only return the topic.
Unlocking bootloader and installing LineageOS on ZTE AT&T Trek 2 HD.