How to get there:
Drive of the highway A8 at exit "Kirchheim-Ost", head to the village of "Nabern", drive through it, use the next right to go on the mountains you see to your right, just when you reach the top, there is a small road on the right to a (former) restaurant ("Engelhof"), drive this road until you come to the second parking lot. ("Wanderparkplatz Engelhof").
Park your car there, walk down the road, bypas the restaurant and follow the trail to "Oberlenningen / Krebsstein" (this is the second trail to the left after the restaurant). After about 1000m, you should reach a crossing, go left there, up the hill. Climb the hill until you reach a second crossing, here you have to leave the trail and continue going uphill through a small forest. On the top of the hill (your GPS should show an altitude of about 800m) you will find a building and a great meadow beside it.
The stash is in the forest next to this meadow, on the highest point of this hill.
On the meadow you should get a very good position with your GPS device, so its advices should bring you very close to the stash.
For fine-navigation, you can use the pictures down here, they show the direct surrounding of the stash. Watch out for these red-painted steel-pilars coming out of the ground: There are two trees next to one of them, the stash is exactly between these two trees.
The total way (to stash and back) is about 5km, you will need about 1h from the parking lot to the stash and back if you walk fast. With searching an digging, you should at least calculate about 2h.
This is only one way to the cache, there is another one starting some kilometers later near another restaurant ("Otto Hofmeister Haus"), this one is a little easier.
Some pictures of the cache:
Stashplace, other view
Stashplace with hole
The parking area "Engelhof"