How to get there:
This excellent web-site on climbing Indonesia peaks should always be consulted.
I started from the small village of Apuy. One can drive there in less than 2 hours from the city of Cirebon. The car (driver) will normally drive you to a small square directly in front of the mosque. From here, one should proceed by ojek (rented ride on a motorbike).
Here is a summary and quick reference to the climbs on this trip.
The ojek will take you from Apuy up to the official entrance of the park/mountain. The small park office will have you fill in a form and ask for (2019) 55.000 for a permit. This is the rate for foreigners, Indonesians are likely a lot less. There is a row of smaller buildings possibly serving climbers, just inside the entrance. Today, they were all vacant.
The trail is quite nice, the first part is wide and really a farm road. This leads to POS I, where there is a building. After this, the trail is more normal, climbing into the forest on the slope of the mountain. A steady uphill passing several "POS locations", finally steeper with some (very) easy scrambling to reach the crater rim. The crater itself is quite deep and very impressive.
The summit (ie. highest point along the crater) is located to the left, ie. one should walk along the rim clockwise. Most Indonesian climbers just go to the rim, few are interested in the true summit. This shows as the crater trail is quite small and partly overgrown. It stays on the rim, but also descends slightly (left) on the outside in order to circumvent difficulties. The summit itself has and old marker, but otherwise there are few signs marking this highest point.
Once at the summit, one may as well continue around the crater rim to do a full traverse.
I left my hotel at 0500, the drive to this trailhead should be about 1.5 hours. We arrived in Apuy around 0630, organized an ojek that brought me up to the park entrance shortly before 0700. Forms to be filled, who knows if I wrote it correctly, all items specified in Indonesian only. The payment was 55.000. I then started walking at 0705. The climb was nice and I really enjoyed it. I made the crater rim in 2:55, not bad ascending about 1650 meter. The complete crater traverse including a 15 minute break at the summit, took about 1.5 hours. Several spots offers good views of the crater, one can also see the big volcano Slamet further north. It was windy on the crater rim, but this could hardly be felt once below it. My descent back down to the entrance took 2:10. No ojek there, but after walking for about 5 minutes I passed a farmer that quickly agreed to serve as ojek and get me back down to Apuy.
Overall, this was a near perfect day with good trails and good scenery. Dinner with Heidi and a full size Bintang (ocal beer) would complete the day.