- Make sure your Glo is charged.
- Download the firmware from here. Make sure you chose the one for Kobo Glo (or Glo HD if that is what you have).
- Unzip the downloaded kobo-update-4.35.20400.zip file. You should see a folder called upgrade and two other files in there.
- Plug in your Kobo and tell it to connect.
- Navigate to your Kobo with Windows Explorer (or the Linux or Mac equivalent). Make sure you can see hidden items. You want to see a folder called .kobo
- Drag the folder and files from kobo-update-4.35.20400.zip to .kobo
- Disconnect your Kobo
- It should think for a minute and start updating. Let it do its thing.
I try to be very detailed, but this whole process should take you five to ten minutes max.