My 4 week DD and I figured it out the first night home from the hospital. I did have to help her with the latch and still do most of the time. If she's nursing on my left side I lay down then prop myself up on my left elbow, I use my right hand to lift her up slightly supporting her head and latch her on. I think sometimes I use the supporting arm's left hand to help out. I do need light to see when she opens wide so we have a night light on all night (I also needed more light in the beginning so I had a small flashlight nearby). After she's latched I slowly lay her down with me then make sure her nose isn't pressed into my boob.
I made learning this a priority sense it was so wonderful once I figured it out with my son at 8 weeks. I'm small chested so maybe that helps with the technique I use to latch her on.