How did Lord Voldemort do to make his face snake-like?

Voldemort have a snake like face because he continuously splitted his soul (into 7 pieces) and each time he did that, he lost some of his humanity and revealed the snake inside

I'm not exactly sure but I think it was from splitting his soul. That just made his features snake-like.

Or were you talking about how did Feinnes do it in the movie?

because when he tried to kill harry as a baby it rebouded hit him and thats how he got his snake face

because he split his soul into 7 horcriuxes and when he did he lost the huminity and reaveled his snakey side

Lord Voldemort is the false identity created by Tom Marvolo Riddle to hide behind. His "friends," many of whom later became Death Eaters, referred to him as such during his Hogwarts days.
Riddle was afraid of Death. He wanted to live forever. Thus, his plan to create Horcruxes. He asked Slughorn about them, wanting to know what would happen if he made seven. Slughorn replied that Riddle's soul would become very unstable, a warning Riddle should have heeded.
Riddle also liked treasures, which probably led him to Horcruxes as a means of living forever. He loved Hogwarts, considering it a second home. As a result, he sought objects from each of the founders, and a few other things, and made them Horcruxes.
Over the course of this, Riddle lost more and more of his soul. This may have contributed to his less-than-human appearance. It may also be of Riddle's own making.

I do hope this answers your question.

He created it by splitting his soul