There have been a few posts on the subject and tonight we attempted successfully to punch out a second hole for our 24" single apron front domsjo sink.
A few words of Caution - wear eye protection - those shards fly fast and far - I got hit in the forehead and was standing back taking photos.
I might also suggest wearing gloves whilst doing it - hubs cut his finger - trying to tidy up the new and jagged hole
Our sink did not come with stickers indicating where the holes are to be punched out.
Here is the sink just out of the box.
Photos of punching out a second hole in 24" apron front Domsjo
Note the notches underneath it
Photos of punching out a second hole in 24" apron front Domsjo
Photos of punching out a second hole in 24" apron front Domsjo
Photos of punching out a second hole in 24" apron front Domsjo
Photos of punching out a second hole in 24" apron front Domsjo
TA-DA all done - all is good - the soap dispenser cover plate covers up the ugly jagged hole !!
Photos of punching out a second hole in 24" apron front Domsjo
Hope this helps someone!!!!
Treasure the people in your life, not your possessions. 
