You can't clone autos. Don't even try because it just won't work. I would also advise not to top an auto - this is FAR too stressful for an auto and will most likely result in the plant giving you absolutely nothing. The only thing you should be considering is some LST (although I accidently did an HST on one of my autos with 4 weeks to go to harvest and that stem & bud survived quite nicely).
Be gentle here... autoflowers are pre-programmed to do their thing... you can tell it where you want it to try growing (i.e., LST) but beyond that, they have the minds set and anything stronger will destroy their plan for themselves.
Good luck -