what plans does mile have to free Mae from jail?

Miles’s plan to free Mae from jail is to have Mae and Winnie switch places so the constable does not take Mae. Winnie can't be killed because she is immortal.

Winnie suggested Miles that she'll cover herself in a blanket so she will look big to the constable at night time.She told miles to screw the iron bars of the jail and free Mae Tuck.