1)You can park your car at the following coordinates right across the border (in Germany):
N52° 07.931 E6° 52.576
2)Next walk to the following location by using the coordinates mentioned below:
N52° 07.924 E6° 52.384
Here you'll find a border-pole with a 3-digit number on it following by a letter. The 3-digit number is the unknown value "A" which you need in the formula down here.
3)The cache location is located at the following coordinates:
N52° 08.X E6° 51.Y
Where X=864-A and Y=126+A
CHECK: distance between border-pole and cache is approximately 516m.
4)Don't dig or lift the whole cache, just unscrew the lid of the barrel to open it.
Good luck and enjoy your hunt!
Greetz,
Kora, Gestel and Jackoo