as I know you can patch the MAIN with Gslide and after that flash it to the phone, this way you allready have a patched MAIN witch you can flash onto the phone anytime. I don't think you can make a backup from the phone.
I am playing with Gslide now but there are several "header" files - how to detremine which of them to use?
Is there any suggestion for W810 CID49?