Canon ip3300

[mrw]

I have two Canon printers that both will not power on. I managed to disassemble the plastic case and clean out the printer heads. My problem is that I can't figure out how to reassemble the plastic cover to the printer. It's all down by snapping together tabs but I can't get the printer back together.
Pictures or a good description would help.

Thanks

 

[mrw]

Follow up to Canon ip3300 printer

I have it back together and finally the printer powers on. The problem is that there are no ink cartridges installed and the cartridge holder does not release when the access panel is opened.The cartridge holder is locked in place and inaccessible without disassembling the printer.

Any ideas???