Just how is this made possible? Well, using the All-in-one toolkit, it will go about installing the relevant HTC drivers onto your Windows computer, performing the entire gamut of HTCDev steps that are required to unlock your bootloader, in addition to flashing a custom recovery afterwards.
Some might beg to differ and claim that this does not deserve to be called an all-in-one toolkit, since there are no visible options as to install a superuser, and neither are there any instructions provided for post-recovery. What it does, however, is to get rid of all the formalities for the uninitiated, making it the perfect tool for those who are too lazy to look for the relevant drivers and recovery files. The toolkit comes with TWRP 2.7.0.2 for the recovery, but you do have the freedom to install your own if you so desire.