There is no spell for that but you can always get a perm or do some chemical relaxers for your hair to change the texture
From my understanding, magick cannot create any physical changes. No eye color change, no hair color or style change, no race change, no weight change, no sex change.
For these things you will need contacts, hair dye, a flat iron, surgery, and for changing your race that just isn't possible.
There are things such as protection workings, love workings, money workings, and so forth that can be done. But the reason why is that they do not contridict nature.