You're welcome! I took the Hehr 4900 series
windows from my
boler apart so if you have any questions, let me know. I can tell you that the screws that hold the frame together are usually fused from corrosion (steel on aluminum). It took a lot of PB Blaster, heat, patience and finally a Dremel tool to get them removed. I highly recommend that when you get ready to remove screws, buy really good screwdrivers or screwdriver bits. Do not use the cheap ones, they will strip the heads of the screws.