That vinyl siding stuff can or is typically placed on with silcock in place. So I suspect you can remove a portion of that plastic vinyl box with a little effort, if need be.
Looks like that fitting was pulled in from the basement side, so maybe you have some room to move that line in or out a bit.
In any case, the first thing you must determine is what type of connection(s) you'll dealing with. It may be possible to unscrew the valve. Can you see it from the inside?