Here is a run-through on what to do...
1. Start at the plaque and look at the last word and note it down and then take 20 paces South to the Irvine Stone
2. Go North East from the Irvine Stone to the Bridge
3. Look for the "Troll" (Cache) under the bridge and note down what it says inside it
4. Go SouthWest to the ladies toilets and note down what it says on the external door
5. Now it is time to find out what the coordinates are!
55°47'C.4"N 4°51'D.2"B
D= Add the first, third and fifth NUMBERS on the toilet door to A (found in Step 3)
B is the first LETTER on the toilet door
C is the last word on the plaque (step 1). Assign the corresponding numerical value to each letter of the word, where a=1 b=2 c=3 etc, add these values together and subtract 10
Hopefully you should have the Final Coordinates!!!!