The way i found out about getting ontop was through the Rocket boots / Parachute cloak. (Requires Engineering)
Simply follow these pictures:
Step 1:
ImageShack - Hosting :: step1hl6.jpg
From here use your Rocket boots + Parachute cloak.
Step 2:
ImageShack - Hosting :: step2yf7.jpg
Now you're up.
Heres something extra. From here once your Boots are off Cool Down you can repeat and make it up there but mine wasnt so i just gave you a pick of where to go.
ImageShack - Hosting :: step3ag6.jpg
I didnt see any posts on this so i guess here it is.
If you arent an engineer heres another way to get up there:
[ame=http://www.youtube.com/watch?v=vXAMyNsGuNY]YouTube - [WOW] How to ; top of STV arena[/ame]
I didnt make this one, I found it while looking for reposts.