Why do you need to downgrade under Luma3DS CFW?
Do you have Arm9LoaderHax?
Are you in the middle of Plailect's Guide?
If so what step?
Are you trying to downgrade to 2.1 or 9.2?
What are you doing that needs this?
There's not nearly enough information provided to adequately answer your question.
Please edit your original post to be less stupid, or don't try to blame us when you screw something up.
What you are doing is like walking into a hospital and yelling "WHAT IS WRONG WITH ME, FIX IT" at a random doctor in the hallway, without telling anyone what your symptoms are, what medicine you've been taking, or what your name is. Ridiculous, in other words.