You dont need w/ex for a History degree.
You need to show that you have an acdemic interest in the study of history at degree level.
You can try getting some customer service w/ex at a museum, archive, national trust, english heritage, tourist site etc but it wont teach you anything more than working in a shop etc. Or get a week in an office/ coffee shop/grocery shop on your nearest Uni campus - that will at least introduce you what it its like at a Uni.