I use this hex tool.
How to disassemble and clean HP C7280 Scanner Glass Mirror
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove the top cover.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove these item by pull out. I don't know what it is.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove these item by press at the back bottom.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove these blue wiring strip by pull out.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove these 4 black screws. Now you can move out the top feeder.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove these item by a screwdriver. Now you can clean the glass of the top feeder.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove the panel mask by use a screwdriver lever up at the corner.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Remove all 7 black screws. Now is the hardest step. Remove the panel off.
Re: How to disassembly and clean HP C7280 Scanner Glass Mirror
Now you can take out the scan glass.