How do you open a closed path in CS4?

Answer 1

Delete anchor point. Choose Direct Selection Tool, click on path to show all anchor points, then click on one (where You want to open path) to select it. Selected anchor point is filled with black. Then hit Backspace or Delete. If Your path have only few anchor points this will delete big portion of path, so use Add Anchor Point tool to add two anchor points, one above and one below anchor point where You want to split (open) path. Click on middle anchor point (after creating two addition) to select it (in other words to become filled with black) then hit Backspace.