@Hyoretsu has a very good guide for installing Safehax/Fasthax in his thread. I would recommend using the written guide over the Youtube video since the video is a little harder to follow since it's a little out of order and not right from square one. You won't be getting any unnecessary files or somebody else's OTP since his guide links you to the sources for all of the programs and gets you the 2.1 transfer right from @Plailect's guide. This is the safest way for you to attempt setting up A9LH (besides the original guide by Plailect, but I believe it's pretty much the same). Look at the success rate in the poll, plus the guide has troubleshooting steps which you won't find in a video guide.