First, you have to be in Indonesia.
From the United States, Europe, Australia or elsewhere, you can swim, walk, or better yet, fly. With Jakarta as your destination.
From Jakarta or anywhere in Bandung:
Take Jalan Tol Padalarang - Cilenyi (direction: to Cilenyi).
Exit Mohamad Toha
Turn right, keep strolling until you're under the bridge / overpass (kolong jembatan!!!).
Stop immediately after passing the bridge
On the left hand side is GPdI Cigereleng (sebelah tukang tambal ban :p).