Use the Edit menu > Edit Shells > Remove Joints from Shells command to remove selected joints from the edges of shell objects.
Click the Set Display Options button and uncheck the Invisible check box in the Objects Present in View area of the Set Building View Options form to turn on the display of the joints in the active window.
Click on the shell object from which joints are to be removed from the edges.
Click on the joint(s) to be removed.
Click the Edit menu > Edit Shells > Remove Joints from Shells command. The program will remove the selected joint(s). If a joint was not colinear with the remaining (unselected) joints, the shell object will be reshaped.