There are two testing days. Paper tests and Assesment Center.
Paper tests are what you see on the Airways website, they just become more difficult.
Assesment Center is a product called 'Sure Select' designed by Airways, and I believe has been sold to Airservices, so most of the tests are very similar.
1. Aerodrome simulation
2. Radar simulation
3. Computer based testing (spatial reasoning, maths, short term memory etc)
4. Group exercise
5. Interview