Canon Perfect Binder A1 Troubleshooting Manual page 230

11) Remove the 10 screws [1][2] in total, and remove the rear stay [2].
[Reference] When attaching the rear stay [2] later, the 8 screws [1] out of the removed 10 screws [1][2] are reused, and the
remaining 2 screws [2] are replaced by the 2 button head bolts (M4x10) inside the kit.
12) Remove the screw [1] that fixes the cutter drive assembly.
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