Screenshot does not need a patch; it just needs a line (or two) to be added to the Kobo eReader.conf file.
Code:
[FeatureSettings]
Screenshots=true
This file is found in the .Kobo\Kobo directory of your device.
Be sure to edit with an editor that is aware of Unix style end-of-line conventions. (Using Windows, Notepad++ is an excellent choice).
If there is NO
[FeatureSettings] section add both lines, otherwise just add the one line
Screenshots=true after the
[FeatureSettings].
After this change has been made, the power button will take a screen shot. To power the device off simply remove the line
Screenshots=true.