[hypoxia]

The movable windows that open are easily removed and repaired but the fixed glass access to the seal would be difficult.  There is no frame to support the glass.  It was explained to me the temperature, pressure changes and wind buffeting are constantly working on the adhesive sealant.  If the glass gets loose from the sealant it can fall off going down the road.  I had one small window panel that was loose & I had to tape it to the inner pane to avoid losing it.

I would be afraid to mess with the seal for fear of causing problems.  Mine are all sealed now, hopefully they last a while.  I do travel at altitudes below sea level and the highest passes 11,000' + so the window sealant gets a workout.

They all do have 78% nitrogen in them