Watch the Sub a Third Arrangement online guitar lesson by Fareed Haque from Solo Guitar Handbook
There are plenty of spots where a minor chord can replace C major. Try Em or Am on "Grace", or also on "Sweet" . Note when I play the arpeggiated chords sometimes I play the MELODY note first and then the chord, instead of just strumming from bottom to top, as we typically do. This creates the illusion that the melody is holding over, separate from the chord, on the top of the chord. It simple but if you use this basic trick, your solos will sound magical! Check out the chart more examples of this principle!