( U. W8 I- j6 y1 L/ U* o, Rthey have a special tool to force in, just right beside the screen, or simply jsut buy a package with tool and screen. ; Z4 T' l1 K# @/ x/ ?9 O: y3 } . }# k- e5 x! k. Q: T( D O( {' Xjust be careful the size and the length, there are 2-3 different size, for patio door or for window.