Well, the adventure was short enough . I am through . Not Mojave though. It is High Sierra.
I followed below link:
and downloaded below installer:
and followed below tutorial:
Everything went according to the plot and now, my PC is worth every penny .
Thanks to you @Mark for kick-starting me on this project.
Thanks to everyone else, whose posts/videos helped me to get through this.
As for Mojave, I will re-visit when AMD Kernels are available.