More than once, I have been ready to do a rolled hem on my serger and then I couldn't find the book. It took me a while, and some time spent reading library books about sergers so I could better understand what's going on with that machine, but I figured out how to adjust from regular seams to the rolled hem settings. Here's a picture of my serger (a trusty Brother 1034D), ready to sew a pretty rolled hem:
And here are the steps, with handy explanations:
1. Remove the left needle. (I left the cone on but the needle is out, for now.)
2. Remove the stitch finger. On my machine there is a lever to press in order to remove the stitch finger.
3. Adjust the dials on the side for rolled hem stitch width (really narrow) and length (really short). The dials have "R" markings for the rolled hem setting.
4. Adjust your thread tensions. This is the thing that I had a big a ha moment about. The rolled hem is going to be rolled down to the underside of your fabric.
You want the upper looper thread to be looser, so it can be pulled down slightly to the underside of this hem stitch. Smaller numbers=looser tension (this one took a while to sink in for me). So if I'm normally on about a 6 for the upper looper tension, I change it to a 4 or 5.
Now you want your lower looper thread to be tighter, so it will pull the upper looper thread down to the underside of the hem stitch. Adjust the dial to a higher number. I adjusted it up to between 7 and 8 from the normal 6.
Finally, your right needle tension needs to be loosened. And I didn't change mine very much. The handbook says to put it at 4 but I've had success with it a bit tighter.
Now you can try this out on a swatch before you actually start on the garment you're hemming. If it doesn't look right, adjust one thread tension at a time and see if you can get it. Hope this helps!
Oh yeah--I also took a photo of the correct stitch finger storage position since I can't ever remember the way it goes in: