You can set the x and y positions of the next/prev buttons inside the addNavigation function and for the play/pause button inside the onSlideLoadingComplete function.
For example to move the whole navigation to top right corner first in onSlideLoadingComplete function we would change the following line:
nextMC._y = Stage.height - nextMC._height - 5;
to
nextMC._y = nextMC._height - 5;
and
prevMC._y = Stage.height - prevMC._height - 5;
to:
prevMC._y = prevMC._height - 5;
and then inside the onSlideLoadingComplete function we will change the following line:
playPauseMC._y = Stage.height - playPauseMC._height - 5;
to
playPauseMC._y = playPauseMC._height - 5;
save the file and test.
Similarly to align to left corners you will have to play with the x values 
