A one-day assessment with a tour of the grounds and numerous group tasks; all quite simple and easy - stuff like hanging up a pile of unorganised stock onto shelves and hangers to make it look as presentable as possible in a given time period, counting the amount of stock in different boxes etc. Then a ~10 minute interview asking about past retail experience and why you want to work at Wimbledon. The selection process isn't difficult per se but they have a lot of applicants so not everyone gets lucky.