1st image just shows the top half of the clock with back removed (after undoing 12 screws). Note the silver motor at middle top.

2nd image shows orange printed circuit board (pcb) for leap year correction. Spray or drip a few drops of contact cleaner on copper tracks of pcb so it dribbles into the gap. Note you can't see the contacts, but the cleaner will run into the gap if you turn the unit upside down. Turn the big cog around a few times to help the cleaning process.

3rd image shows another orange printed circuit board for month adjustment. Again spray or drip a little contact cleaner onto the pcb copper tracks and let it drip into the gap. Again help the cleaning process by rolling through the months immediately after using the cleaning solvent. Dry up any excess cleaning fluid if necessary.