I wish I could help more specifically, but I dont remember exactly what I did that allowed me access- just kept trying
Maybe try this...(dont be offended if any of these steps are ones that you already know or have tried, I am just trying to be as thorough as I can from memory)
Open up super user, then go back to the terminal emulator and enter the "su" command to gain superuser permissions.
Plug the phone into the computer, select charge only, enter ADB through tools (probably "C:\Android\tools" if your Android folder is in the root of your harddrive).
from the prompt C:\Android\Tools, enter:
then you will get the "$" that you mentioned.
enter the "su" command, and hopefully you will get prompted to allow superuser permissions for ADB.
I am pretty sure these are the steps that I took, just had to keep trying.
Lemme know how it works out.