Thanks Tom excellent directions. There is plenty of parking around.
I went early yesterday (21 March) but they have changed the system.
The old system was get the health check first, then make an appointment with DGT. Because of the volume of licence exchange applications, and the health certificate expires after three months, the health centre is now asking for people to book the appointment with DGT first, to ensure the health certificate is valid for the appointment if the DGT start running with a backlog.
With the help of Miguel, who got an appointment sorted with DGT for me in early
April, I went back this morning and 50 euros lighter I have the health certificate. They were quiet around 10:00am. I understand they open at 08:00 now until 14:00.
As others have described, the test consists of trying to keep two black bars inside two curvy white lines, as they move along. The white lines move independently of each other. The black bars are controlled by two 'T' handles, one for each bar. You need to do this for a minute. There were some medical questions about health, then you get a photo taken, then an eye test. The completed certificate is collected from the receptionist on the way out. The staff were very helpful.
Hope this is helpful