I did this last night. I had a hell of a time jumping on to the wall, but I kept at it and finally did it. It was cool to see to view only parcially rendered.
TIP: How to collect everything without getting bogged down.
I'm a female breton with self confidence, and I don't mind walking around in just my underwear if I need to. Before attempting to find the chest I put
everything that weighed anything (amour included), except my soul jems, into the trunk in my bed room. When I found the chest I was able to collect and carry everything worth anything without getting weighed down. I went straight to the enchanting station in Dragonreach and enchanted everything I could. This increased my enchanting and upped me a level
and then I went around Whiterun and sold everything. SCORE