They are held in place by spring-loaded fiction clips. To remove them, you gently pry the screen away from the window to reveal the clips' locations. (Should be two on the left and right, near the top and bottom of the sides.) Again, apply gentle pressure at these points to pop the screen out taking care not to bend the screen's frame. This is not a "user friendly" attachment method. Getting them back in is harder than it should be.
Be patient, slow and gentle so as not to bend anything.
Wright and Penny
2010 Tundra 4X4 5.7L V8
2014 Rockwood 2604WS
Life is a cruel teacher. She gives the test first; the lesson then follows.