As a first step, you are going to need to enable Private Messaging. If you don't see it in the 'Edit Options' of the control panel, you will need to ask a moderator to enable it for you. See the
Requests to enable Private Messages thread to ask for it to be enabled.
Furthermore there is an existing thread to ask for images for Kobo devices. In your case, the
Kobo Glo: Need SD card image thread.