All/Ken (as I dont have Ken's email address...)
I asked Phil ward on your behalf of any special arrangements and got this reply

Tim,

He just needs to park with the Lancias as directed.


Phil

I still think you need a ticket which can be purchased I seem to remember on the gate or in advance

https://www.brooklandsmuseum.com/whats-on/auto-italia-italian-car-day

Read the Brooklands website for more info.

I have done the hill but you have to register (how??) and dont forget to turn right at the end as there is a big oak tree.....

If Ken has more info then wait for that.