So you want to get inside the temple while not fighting the goblin army?
There is few options for you ... first of all, invisibility.
Then you can jump down from the cliff you can acess from Waukeen's Rest ... if you walk to that bridge where you meet Githyanki patrol, but you go south, you can see some smaller broken bridge, only high Str characters are able to jump over it, but if you killed Minthara you should have Misty Step neck ... then you simply jump down (dont even need Slow Fall, its dont hurts so bad, but it hurts) you break the wall and you are in.
