How would I update the Grid Graph from within game?

Beginner Questions
1

I have found the GraphUpdateUtilities Class Reference doc but I do not Understand where to use it. (probably a stupid question)

2

Hi

See this documentation page for more information: http://arongranberg.com/astar/docs/graph-updates.php
You can also recalculate the whole graph using
AstarPath.active.Scan ()
But that is relatively slow (compared to updating just a part of it)