I don't want to lose my link juice for the old urls.
What's the best way to do this? There are a lot of different methods online eg http://wp.smashingmagazine.com/2013/04/08/moving-wordpress-website/
Rather than writing individual 301's, could I move the new wp site to the root directory and add the following to the htaccess file :
# This allows you to redirect your entire website to any other domain Redirect 301 / http://artunframed.com/