The professional (expensive) tool would be something like a GageBilt GBP704E-Cherry Max riveter with the Cherry offset pulling head.
You may be lucky and get that combo on EBay for about $600 (but you could always sell it again afterwards for the same amount).
That said, I've used the methods described above with some success and also had to drill a few out again when the plug didn't pull through.
It's quite easy to make the pulling wedge described above from 3/8" square steel bar. I have a drawing somewhere that I could send if required (edit: drawing added).