Here is a web site that gave me all the info and then some on how to do this.

http://www.mirage-performance.com/sonata/Axles/index.html

There is also a link at the bottom of this page that details the install. The swap can only be done on cars built between '90 and 5/92 as the tranny is changed after that. I came upon this in my search for FWD supremacy and thought I'd pass it on.