Well, I can get Kiel and Ithrorn to offer advice, but it wouldn't be right to give you perfect solutions. However...
1. A normal person cannot climb the walls. You are not normal people!
2. Climbing the walls without being detected is impossible. Unless the distraction works well!
3. Only ONE person needs to get to the top the hard way, then he can drop a line
4. Don't forget that you all have those general purpose utility belts, and while you can't jump ALL the way up, that doesn't mean jumping is useless. Just look at the position Obi-Wan jumped from in the pit in TPM!
(OOC: Ok, thanks Ush)
"Master Gundark, if you don't mind I would like to take the initiative for a while.
"Once the bomb drops we should send someone up the wall. We can use a great many things. The Force is our ally, but we should not depend to greatly on it. Whoever we choose to send up should jump as high as he can, with their grappling hook at the ready of course. While still in the air I would like for you to shoot the grappling hook up over the wall. Then you should have no trouble climbing the rest of the way.
"Just leave the rope for the rest of us to climb up. If we all use the Force we should make it up in no time. I have a feeling that we will do this. Remember there is no try, only do. Now, does anyone have a nomination as to who should be the first to make the jump? This is a crucial part. If we don't get up in time then we might not be able to make it in time before the distraction wears off."
(OOC: How's that Ush???)