It isn't hard getting into the tower, but there are a couple places some people get stuck on (ie finding the button mentioned above to get into the secret storage area, or earlier if they didn't read a book they were given, so didn't recognize it needed to be used at a particular spot, etc).
The D2:ED
walkthrough should be pretty close on quest solutions, though there was some balancing changes in DKS, etc, and some of the details may have been altered.