This Nando's is in the newly extended Beacon shopping centre in the heart of Eastbourne town centre. It's pretty much next door to Eastbourne train station.
The Beacon has its own parking priced at £1/hr but if you are fine with a very short walk, The Junction parking is priced more cheaply for longer stays at £1/1hr, £1.80/2hrs, £2.30/3hrs, £3/4hrs and £3.50/4+hrs - note that this car park closes at 7pm during the week. Both car parks offer free parking on Sundays. All other shops in the centre close around 6pm, so Nando's is accessed from the side of The Junction car park where you just head upstairs once inside The Beacon.