Start by creating a copy of this list on the Wiki, called QA_List_4.6:

http://techbase.kde.org/Projects/Edu/KStars/QA_List_4.2

and making all entries black (untested).

Build KStars from trunk, or install KStars from KDE SC 4.6 RC 2.

Add newly included features to that list (eg: Switch to OpenGL backend, Moon phase calendar) etc.

Test each feature, covering at least 50% of the new full list.

If you have any questions, feel free to send me an email at akarsh.simha@kdemail.net