I have to replace a misted unit on an upstairs window. The window is hardwood and externally rebated. The problem I have is outside access to the window is difficult by ladder due to a sloping porch roof. The glass is 2m x 1.5 and heavy. Would it be possible to manipulate the glass through the opening from the inside by attaching suction pads and then pulling back into place. I would be able to access the window from the outside to replace the beading but would be unable to get the glass up from the outside. Any suggestions please?