I'm not sure there is a command for this..
you could try typing in the following commands though;
1. runscript addtalent 4020 for the rogue talent tree.
2. runscript addtalent 100001 for Deft Hands.
3. runscript addtalent 100002 for Improved Tools.
4. runscript addtalent 100003 for Mechanical Expertise.
5. runscript addtalent 100004 for Device Mastery.
Make sure to type them in that order.
according to
Link it *should* work. (link is to Dragon Age wiki)
Make sure you save your game first near a locked chest so you can easily test it.
If it doesn't work just replace the "addtalent" bit with "removetalent", when removing though, remove in reverse order.
Good luck.