According to Google maps, by road from Eastbourne station to the stadium is just under 20 miles. Haywards Heath is only 13. Eastbourne is just too far to be practical, I think. Polegate, maybe would be the sensible compromise?
Have they moved Eastbourne since I was last there? Haywards Heath is certainly closer to Falmer than Eastbourne is. I can't be bothered to check if Worthing is.
You do realise that those directions were for coming FROM the East, don't you?
Traveling Eastbound, I imagine the best place to come off the A27 is at the university / stadium junction and then re-join it heading West. You can then follow those directions. You might want to be early, though, as...