It appears that my aluminium windows don't use the more common type of seal. They appear to slide in as a solid backing prevents the seal being prised out. They seem to be similar to this: http://www.amesbury.com/divisions/extruded-products/parts/200/3647
My question is: How are they removed? A casual look leads me to believe it could be a nightmare requiring a lot of dismantling. Please, somebody tell me there's an easy way staring me in the face.
Window photo 1 https://goo.gl/photos/gtX5RbPSRgfTdzhD9
Window photo 2 https://goo.gl/photos/CTaRMeHKCfi6CG757