Canon iPF800 Series Service Manual page 171

7) Lift stopper [1] in the ink tank lock lever and raise ink tank lock lever [2] until it won't go farther and then push it to the front.
8) Remove all ink tanks.
Put the removed ink tanks in the plastic bag with the ink supply part [1] upward and close the opening.
[2]
[1]
F-3-12
[1]
F-3-13
[1]
F-3-14
Chapter 3
3-9