There are two A4 plastic covered notices fixed to trees on each side of the track, they are at head height so you cannot miss them.
If in any doubt ring the river keeper, his number is on the website.
The signs position is located at the same place as indicated on the map that is on the website, I would suggest that you print off a copy and have it will you and it will enable you to know where you are on the fishery.
Write your names and car make, colour and number on the outside of an envelope and put it through the door of the keepers cottage as you enter the fishery (last door on the left before the salmon anglers room), he is usually on the fishery very early, but will collect it when he returns.
Don't worry if your tickets do not arrive, the keeper will have an uptodate list of all the day anglers and do a cross reference on the CCTV security system without having to track you down.
Its the norm for the keepers on these game rivers to just appear behind you when they want to see who's on their river, and he will certainly come and see you at sometime, then you can ask for an update, but be assured it won't be "you should have been here Thursday".
Have a great trip and I'll call in and see you if I've got the time.