In reply to purple sue:
Hi Sue, I hope you are well and climbing well.
I've not done this on sports routes, but I have soloed bigger stuff. Here is one suggestion.
1. Assuming one can't build a ground anchor? If you can, this removes some of the complexities of the next step.
2. tie in. clip stick first bolt with a screw gate. put grigri on. hoist/climb to first bolt. hang from a daisy clipped to the screw gate. You are on a 2:1, so should be able to hoist yourself over any steep starting bulge. If not steep, just tie the rope to the screw gate before you clip stick it up.
3. untie your tie-in knot and tie the rope to the screw gate, leaving a tail that reaches the ground!
4. clip stick the next bolt and repeat
5. you now have a two-bolt anchor
6. clip stick the next bolt with a draw (and the rope), grigri up to it (use a back up knot)
7. daisy into the third bolt, daisy it and tie an overhand (in the rope above the draw) and clip it to your belay loop (this is a back up)
8. remove grigri (or pull a loop of rope through it), clip stick next bolt. attach the grigri again. remove overhand. attach back up knot below brake hand, grigri up. Repeat at each bolt
I normally use a pair of traxions on one line when top rope soloing, so I would tie the rope off at the chains.
if the route is overhanging you will have a problem grigri-ing up. So put your ascender above you, run the grigri brake strand up to a krab on the ascender and you have a 2:1. If you put a sling on the ascender you have something to stand on. What you don't want to do is attach that top ascender to you. If a bolt failed, you would be loading the teeth of the ascender.
Always use a backup knot and practice on top rope at a climbing wall.
All the best, and drop by Devon sometime