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 on either side of the door. Does anyone have specific knowledge as to how the removal and replacement should be done? Thanks.