"Could you provide a fully worked example of how a car park with, say, 100 spaces in it could be adapted to provide a charging point for each space, with a connection to the grid for, say 2/3 of them to be charging at any one time?"
Not all of the spaces would need to have the option of charging. The other thing is to offer the lowest level of charging so the greatest number of cars can charge at once and put the charging spaces to the rear of the lot so they don't get "ICEd" as frequently.
I don't always need to put petrol in my car and when I have an EV, I won't always "need" to charge it. If I can get a few free electrons while shopping, that's a bonus, but I am more likely to have been charging at home and in good shape for having enough range.
For a multi-level car park or paid parking, you could be asked to pay more for a charing space, a bit more than that for a higher level charging spot or the minimum for a space with no charging. Your choice.