This is almost useless as it's pretty easy to get a group for MT on the PTR, but if you just wanna run in and get to the orb/try this for yourself it can be fun...
Zone in and clear the first two mage mobs, then the warlok/physician pat (easy as mage).
Next, use invisibility past the middle tree into next hall (Looking at first boss as seen below)... you CAN get past first boss and blink through the door by using Just invisibilty if you time it just right, but its kinda hard... Take an invisibility pot if you can't do it.
Blink through door up the right steps above ^
Door:
Looking back:
Tyrith is down the hall on the left, before 2nd boss; you can turn in Magister's Terrace here, and he gives you a quest to activate the orb, which is right past the second boss.
You can also blink past the second boss's door, and use the orb - watch out for pat... Invisibility cuts it close there too...
As I said it's almost useless, but kinda fun to see how far you can get solo :P