full posts/ on front page

hi, I love the look of this theme; clean, stylish and overal awesome. The only issue I have with it, is that I would like to have the option of having full posts or a read more link on my posts instead of the standard summary this theme seems to use. The other post in the support section about the front page was limited to x amount of words, but this is not exactly what I have in mind.

If anybody could explain in layman’s terms how to do this, that would be very appreciated. Thanks so much!