would some Casio/watch expert know if it's possible to replace the face plate on these watches? I love the simplicity but I don't like all the text outside the watch itself like "Step tracker" and "Water Resist".

I think the appropriate way in this case is to cover it up with black tape.

the face decal is printed on the inside of the crystal (plastic). it can be removed with solvent and replaced if you find/make a replacement.