change out of (something)
To remove an item of clothing in order to put on a different one. The minute I get home, all I want to do is to change out of my work clothes. Change out of your wet bathing suit and put on something suitable for dinner.
change out of something
to take off a set of clothing and put on another. I have to change out of these wet clothes. You should change out of your casual clothes and put on something more formal for dinner.
change out of
v. To take off some clothing and put on other clothing: You should change out of those wet clothes before you catch a cold!