As shown in the figure, release hook (1) (left button) and hook ( 2 ) (right top toward the back) of the roller cover, and then lift up the cover. This will allow you to remove the cover.
Swipe the ink cartridge 2 or 3 times on the Built-in Nozzle Cleaning Pad shown in the diagram below. If the text or bitmap still appear fain after this operation, replace the ink cartridge.