Remove and replace kitchen window with just caulking outside
It most likely has a window flange on it that you'll need to remove as well which is probably buried behind the siding. If you have a reciprocating saw you'll probably have to cut the flange off. An alternative that I've seen is to to remove the glass and then collapse the frame pulling nails and all with it. If you don't mind putting a frame around the window then you cut a section of siding off just wide enough to get to the flange, remove everything and then put a frame around the new windows to cover the siding that you removed. You could even save the siding piece your removed and put it in place under the frame.