The clear lens over the display protects the display itself, but it is an integral part of the front housing.

You can find a replacement here:
promobility[DOT]net/html/blackberryparts.shtml

Instructions here:
blackberryforums[DOT]com/general-8700-series-discussion/27159-took-apart-my-8700r.html?highlight=8700+housing

And a Torx driver you can find here:
bbrepairshop[DOT]com/Parts8700.html

Sorry, not enough posts to be able to post a URL yet
Mark