[Plugin: NextGEN Gallery] Add Navigation Arrows to NextGen Scroll Gallery

I’m not good at modifying codes.
Is there someone know how to add navigation arrows to every nextGen Gallery.

Here’s the gallery sample post
http://www.savvysassymoms.com/ziplining-in-california-with-navitat/

And I want to be like this.

http://blogs.babycenter.com/mom_stories/the-cutest-babies-of-2012/

I hope you could help..

http://wordpress.org/extend/plugins/nextgen-gallery/