Even with the tour I was lucky to get in a waiting list and have a guide from CERN. Indeed you need months in advance to get inside and I am not sure they can take you all the way down to the detector.
A few phone calls and anything becomes possible (in particular to make this happen for STEEM ;) ). For the next time, please let me know in advance so that I could potentially arrange something for you.
As far as the physicist told us, a tour up close to the detector were not possible at the time due to some cooling/preserving procedures. If I understood correctly that is.
This may be the case for ATLAS (which is the one you visited). But this is definitely not the case for CMS (the one we will visit). I am less connected to ATLAS (I have friends in there, but I am a member of the other collaboration, which helps).