From the eastern side of the Soca-Tolminka confluence (upper end of the connector to road Nr.102), follow a riverside singletrack at Tolminka river. After 150m, you have to climb up some meters to the right and cross Tolminka at a suspension bridge.
Ride on a doubletrack to the confluence and take the lowest trail along Soca river. In the beginning, the riverbank is steeper, so the trail is little trickier here. Later on, the trail is smooth (stay near the riverside), leading up to a small road at a plateau beside cemetery of Tolmin.
At the northern corner of the cemetery there is a poorly marked, visible path with wooden steps (rideable - take care when it's wet!) that brings you down to the riverside. The trail ends at road Nr.102, directly at the northern end of a bridge, crossing Soca river.