What did you name the folders that you put the models in?
You need 2 folders. 1 folder named "admin_ct" and 1 folder named "admin_te" These 2 folders need to be inside the "players" folder.
Here are the specific installation instructions.
INSTALLATION
##------------------------------------------------------------------------
## 1) Unzip (which you may have done already)
## 2) Place 'amx_adminmodel.amxx' in 'cstrike/addons/amxmodx/plugins' <---Did you do this? ## 3) Add a line in 'configs/plugins.ini' containing 'amx_adminmodel.amxx' <---Did you do this?
## 4) Put the 'admin_ct' and 'admin_te' folders into 'cstrike/models' folder