If you have not cleaned the entire station, at least wash the parts of the cog assembly, and mop up some of the ink in the station with paper towels or shop rags.

Poke the bar in through the left side, then place over it the replacement spring and the spring retainer. The clips of the retainer go towards the spring. Do not slide the retainer all the way home yet.

Place put the sliding cog over the bar, taking note of the direction. Slide the spring retainer home. The sliding cog will locate in the hole in the housing on the right.