I have several wooden exterior patio doors with full-length thermal windows which need replacement due to degredation of the seal, causing fogging within the window.  I have the replacement glass units, but I am uncertain how to remove the old glass.  I cannot determine by visual inspection whether the window trim is removed from inside or outside the door.  I don’t see any brads in the trim on either side of the door.  Does anyone have specific knowledge as to how the removal and replacement should be done?  Thanks.