It'll be a lot of work.
As well as the physical bits, dash, steering, pedals, etc., there's also the wiring loom which won't just turn upside down and a body computer that might get upset. If rear fog and reverse lights are one-side only, these may need changing, although if made for the UK market should be ok.
My thoughts would be find a similar age van that's been written off and use it as a donor for everything, including wiring, keys if necessary and engine and body computers.
Why do you need/want to convert it?
What issues do you thing LHD will cause you. People may be able to advise how to live with these.