With a huge amount of wallpaper paste and a total disregard for the awful bumpy, wrinkly, ill-fitting mess you'll end up with. Don't bother trying. If you don't like the Artex your only choice is to chip it off or skim with new plaster to a smooth finish.
I used a product called X-Tex. This was very safe as it didnt contain solvents and didnt even effect the plaster board underneath. Left in on overnight and it scraped off the next day with out any effort.