you can get the glass sets from places [https://www.ebay.co.uk/itm/HP-Officejet-Pro-8600-PLUS-Printer-SCANNER-GLASS-SET/162670056485?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D46150%26meid%3Dbcf0254882fb4dd1a006a8d643003ee4%26pid%3D100623%26rk%3D1%26rkt%3D3%26sd%3D231800190150&_trksid=p2047675.c100623.m-1|like this] HP does not supply service manuals for printer / scanner hardware for disassembly. [https://www.youtube.com/watch?v=X6mZQ2VWVQw|This video] might help with the job. To get to the scanner glass you will need to remove the front display which can easily break your printer.