Hello there, bpbiv.
The following Knowledge Base article should provide some assistance in redirecting iTunes:
Since you already have the folder located on the external drive just point it to that location, you wont need to perform the portion of creating a new folder.
If the issue persists and reinstalling iTunes is necessary, refer to this Knowledge Base article as the uninstall/reinstall steps do need to be performed in a very particular order:
Thanks for reaching out to Apple Support Communities.
Hey I followed the instructions, I pointed itunes to the folder in my external drive, I consolodated the files and nothing is happening and I still am not seeing anything from my external in my itunes - no music, no apps, no nothing except the two albums located in my pc internal hard drive.
Any more suggestions? Because my iphones new os7 update is giving me pop ups telling me to sync with my itunes, and itunes is wanting to erase my phone telling me my phone is synced with a different library. All because it will not read my external drive data, even though it is showing up in my advanced preferences of itunes.
Why does everything have to be so freakin difficult?