Inner Dual Wheel Extenders Impossble to install.

Since I got my two inner wheels replaced more than a year ago, I have not been able to check the air, we picked up some of these Air Guard extenders in Alabama, thought it would be easy enough to install, the instructions say to place the extender though the hand hold and thread onto inner wheel valve as shown, seems easy enough except for two problems 1. you can't fit your and though the hole and 2. you can't align the extender with the valve even with the use of long needle nose pliers even though the side between the inner and outer tires, so does anyone know if there is a trick to this, or does the out wheel have to be off when these are installed?
Thanks