vim:

step 1: type ci(. step 2: type what you want to replace with. step 3: press ESC.

notepad++:

step 1: press Ctrl-H. step 2: type \([^)]*\). step 3: press tab. step 4: press (. step 5: type what you want to replace with. step 6: press ). step 7: move hand to mouse. step 8: move cursor to and click on "Regular expression". step 9: press enter.

Do you have another example?