Engine oil - clean unused (Orton CA10)

Does anybody do their own vehicle maintenance? I bought this 20 litre bottle of engine oil and used a lot of it, but I'm never going to use the remainder. There are about 3 litres of oil left probably - you can hear it slopping about in the bottle when you shake it. It's clean, unused and has just been sat on a shelf for the last 5 years. Collect from Orton.