Under the top cover, You need a 7mm allen key to remove it + you need to remove the breath...
Under the top cover, You need a 7mm allen key to remove it + you need to remove the breather hose which goes across the top of the engine.
Try ebay.com for a manual...There are usually several available from the N.American site and they can usually ship to the UK within a week or so.
Seeing the S280 was never released in the USA, try a search on S320 instead. The car was identical is almost every way. The two models share the same engine only with a smaller bore.