Apply downward pressure on the retaining spring.

Use a spudger to release the plastic tab holding in the retaining spring.

Once the edge of the retaining spring has cleared the plastic tab, you can slide the retaining spring out of the printer.

The retaining spring can only be removed out of one side of the printer.

Clearing the plastic tab holding the retaining spring in place requires a fair bit of force and coordination. It is possible to damage the plastic tab.