If install is grayed out...
There are two ways to make INSTALL turn from gray to black, thus allowing you to install the update.
Option 1: Press/tap your home button (on LG's it is the circle at the bottom of the screen) to get out of Pointcare. Then open the Pointcare app again. Now install should be black, allowing you to tap it and complete the update.
You shouldn't need to log in again when doing option 1 but if you do, please try option 2.
Option 2: Swipe down from above your screen to show the notification shade. Tap any icon at the top of the notification shade to turn that feature on/off, then tap it again to put it back to how it was. Then tap CLEAR ALL in the lower right corner of the screen. Now you should be back to Pointcare but install should be black, allowing you to tap it and complete the update.
For additional help
Click this link for a mobile help page: http://cornerstoneguide.com/mobilehelp.html