You'd like to transform :
...and your cursor is here:
Type v2i)c to select everything between the outer parenthesis, but not the parenthesis, c to change it then type argc != 2, a.k.a. v enters visual mode, specify you want to go 2 levels of parenthesis up then i) to select everything between the block and c deletes everything selected and puts you into INSERT mode.
Use a) instead of i) to select everything in the block and the parenthesis.
Type :help object-select for help with this and related commands. Type :q to exit help.