EDIT - ADDITION:
If you just remove the right cover (see diagram Figure 5-4: Right Cover) if memory serves me correctly, the printhead carriage is right there in front.
I seem to remember that it can be opened and the printheads removed.
Now if this is the case, I would remove all the printheads, close the carriage cover, replace the right printer cover,
Then, take out all carts.
The printer should attempt to initialize, and the carriage should move. It will ask for cartridges, then printheads.
But, if you suspect a bad printhead, I'd get a new one to replace the offending printhead before trying to run the printer.
Hope this helps.