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 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.
The only place that I know of to get the genuine Motorola Droid Razr Maxx Battery and the Droid Razr Maxx Back Battery Cover is Cellphone Repair Shop. But what you really want is the complete kit to convert your Droid Razr into a Droid Razr Maxx. They have a complete step by step video also on how to do it yourself of you can send it to them for conversion. Everyone that has already purchased their kits and received them are raving about them.
You can find the Genuine Motorola Droid Razr LCD Screen Assembly at Cellphone Repair Shop. The link above is for the Black one but they have pretty much everything for the Droid Razr and it all appears to be original. Here is a link to all their Motorola Droid Razr Parts