As long as you read it carefully and follow it word for word you should be fine. There are some cases of bricks but mostly for N3DS. I did this on my N3DS XL and was scared the whole process. But in the end I got my OTP.bin and am running a9hl with reinand It seems to be a better chance with the o3ds bc it actually was around for 2.1. You get to skip the scary part of unbricking a downgraded 2.1 emunand and flashing it to your sysnand. For a N3DS user myself, thats the part that didnt feel, comfortable doing. If you do try it with your o3ds good luck!Just finished reading the guide for a9lh o3ds and 2ds and woh, i don't know if i can do it.