replacing new construction windows from the inside
recently i had a contractor to the house to give an estimate on vinyl siding, the first two floors of the house are aluminum, the 3rd is older vinyl. While he was there i mentioned i was thinking about doing the windows as well but at a later date because i could not afford both projects at the same time. He mentioned that my windows were new construction windows and so replacing them when the new siding goes up is the best way to do it. the current windows are double pain vinyl replacement windows but they bow toward the center of the window between the locks, the locks don't line up properly anymore, and the windows are drafty.
Can these windows be replaced from the inside by removing the trim or do i have to take the aluminum trim off from the outside and replace them that way? I have not removed the inside trim due to the age of the wood itself.