We recommend to keep Lightroom on the same drive where you have the operating system installed.
You can install Lightroom CC 2015 to a custom location.
Prior versions of Lightroom (5.0 and earlier) had to be installed to your local drive and could not be installed to custom location like other Creative Cloud apps.
There is no need to reinstall anything. The location of your Lightroom program and the location of your photos have nothing to do with each other.
To move your photos to a new hard drive just use Finder to drag and drop your pictures folder(s) to the new drive.
You can move your LR catalog to a new drive, too, but that is not necessary.
After you move the photos, go into LR Library module, Folders panel, and "update location" on the folders that you moved.