How can I do this?

Super cheese sandwich

https://www.daz3d.com/hell-princess-hd-for-genesis-8-female

FSMCDesigns

Photoshop - postwork, deformers, a modeling app like hexagon, etc.

AlmightyQUEST

That sounds about right, the person who made it talks about it in this thread https://www.daz3d.com/forums/discussion/261131/hell-princess-hd-for-genesis-8-female#latest

Richard Haseltine

I know Daz allowed the image for the promo, but it seems a bit much for the forum ToS so I'ven removed the attachment.