Next, toss some asteroids into orbit around a single plane at that distance.
Start building solar panel platforms. You have mass from the asteroids, and power from the sun. If you need attitude stabilizers (which you will) ion drives won't be hard to construct. Radiator fins, if needed, can go on the back of the asteroid.
Continue extending the platforms along their orbital plane. I recommend restricting them to a few thousand miles wide at most, but you do want them wide enough so that damage will be unlikely to cut them in half. If you run out of mass, send a few more asteroids over. Or a few moons. Nobody will really miss Io, will they?
At some point you'll discover you have an energy surplus. Start selling this to whoever needs it.
Continue extending. Now is the right time to find an iron planet nobody cares much about, and send it over for raw materials also. You're going to need it.
Eventually your platforms will connect. Now, chances are good you're generating thousands of times more power than you really need. But this isn't "how to get a bunch of energy from a star". We're going all the way here. So now it's time to get a bit crazy.
Build giant ion thrusters on your ring. Slow the ring down. Stop the ring. If you've built it properly, it won't collapse - it'll hold itself up. If you didn't read ahead in this guide, your ring is probably now falling into the sun. Start over, and this time read ahead.
Now build another ring, the same way as the first one, only at a ninety degree angle to your existing ring. There's a few ways you can keep it from colliding - you could build it slightly above or slightly below your current ring, though that might cause problems when you try to connect the two. You could build little gaps in your ring that are still structurally sound but include a hole for this new ring to pass through. I recommend thinking about this before you complete the original ring.
Once the new ring is finished, slow it down and stop it as well. Then connect it to the original ring.
Do this at least one more time. You can build another ring at right angles again. You could build more rings at other angles. It's really up to you.
Once you're satisfied with the framework, start filling it in. You'll need some more planets here, if you haven't already run out. Eventually you'll cover the entire sun with solar panels. Gather the energy. Revel in your newfound wealth.
The sun will, in time, die, leaving a core made out of mostly . . . iron. Reclaim the iron and go build another shell. Done.