Take it from me guys I have tried to install just the glass and it is not possible. All the new phones are coming with the new style preassembled LCD and Touch Screen and are not able to be separated. You best bet is to purchase the genuine [http://cellphone-repair-shop.com/motorola-droid-razr-faceplate-black-lcd-digitizer-assembly/|Droid Razr LCD and Digitizer] Assembly at Cellphone Repair Shop.com
The actuall installation is not too dificult but considering the cost of the part I would pay the $25 to have them install it also.
Hope this helps. Good luck.