See you need guys who play RC cars a lot to teach u this ... I used to change a car body shell evey 2-3 weeks! Okay ... squares and all are easy ... use a Xacto knife to cut out the lines, you need not cut through but score is deep. Once its done then cut through an area then slowly 'tear' the portion out. This can only work with canopy material like LEXAN and NOT what you get from WM stuff, that trype will crack a lot.