I have recently did this. I went from 3.6.5 to 4.4.1 I used this website as a tutorial. http://www.math.ias.edu/~tarzadon/pages/posts/migrating-rt-3.6.4-to-rt-4.0-88.php I also used phpMyAdmin.
--------- RT 4.4 and RTIR training sessions, and a new workshop day! https://bestpractical.com/training * Los Angeles - Q1 2017
