How to unlock bootloader of Alcatel One Touch Idol 2 Mini S 6036A.

Hello, I'm a new user of this community. I was searching for threads that could answer my question and no one was the indicated to do so. So, as you can read in the title, I was wondering how to unlock the bootloader of my phone, because I want to install a custom ROM to change my Android OS to another newer (i.e. 5.1.1). I read some methods that use the Android SDK, but none of them for my type of Alcatel. I came here because I know this is the correct place to find the correct answer.

Thanks in advance for reading.