How to add grace notes to a two note chord that's one octave apart

I need to know how to add a grace note (exactly the same two notes before a two note chord where the notes are exactly one octave apart (similar to playing a sixteenth note octave chord quickly before the main two note octave chord. Does anyone know what I mean? I am uploading a snapshot of the two measures with different types of grace notes needed before a two note chord, one of which is a chord that's the same note an octave apart. I just don't know how to add these special extra notes in front of the two note chords so they don't affect the count value of each measure. The grace notes, if I'm using the correct name for them, are written on the base clef of the first two measures (the bottom two note chords). They are on the first two measures at the bottom clef at bottom of page in the picture. Thanks for your help. David