On the ones I install, I drill through the carrier and op rod with a 1/8" bit. Then I taper the hole on both sides of the carrier, and peen the 1/8" steel rod on both sides, after cutting it about 1/4" longer than the OD of the carrier. It is hammered down into the taper on each side, then carefully ground flush and the carrier refinished.
That's how I do them anyway..... I've seen some where people just used a roll pin. I wouldn't trust that though.
Thanks thats easy enough, now I just need to find a small piece of 1/8" steel stock