Ha! You can't. For those that don't know, the note after the slash means you play that note in the bass. So for G/A, you play a G chord but you play an A in the bass.
Generally those are seen when a bass line is intended. You'll see G, G/A, G/B, then C. Or something. Well, you just hold the G chord and create a bass line of G, A, B, and end with C. Easy on piano, possible on guitar, but not possible on a uke.
What you can do is include those notes in your chord, but not in the bass, since you don't have any bass. So the G would become a G9 (a G chord with an A in it). The C example you have would stay a C, because the E is already in the chord. Sometimes you can replicate that run within chords, but not in the bass. That will mean you're not clashing with the others, but again you can't play bass without bass strings.
Just gesture to your acoustic bass player to do the run while you hold G7 and take all the credit.