How Can I Learn to Say "No" without Feeling Guilty?

https://www.godtube.com/resource/mediaplayer/w6wpzwnx.mp4;https://content.swncdn.com/godtube/2014/08/18/474894/474894_480p_posters19.jpg;https://www.godtube.com/watch/?v=W6WPZWNX;