A hardmod, is a hardware modification, it means you have to open up the 3DS and do stuff to it, so you can get it downgrade.
Here is a guide on how to do a hardmod on a 3DS:
https://gbatemp.net/threads/tutorial-noob-friendly-nand-dumping-2ds-3ds-3ds-xl-n3ds-n3ds-xl.414498/
Then after you have that setup, you would follow this guide:
https://github.com/Plailect/Guide/wiki/Hardmod-Downgrade
You'll probably need an alternative homebrew entry point, in addition to the hardmod.
Basically, if you have a 3DS on that firmware, it complicates things, especially if you aren't good when it comes to soldering or don't want to open up your 3DS.
There's also this thread to find Hardmod installers in your area, they of course charge for the service:
http://gbatemp.net/threads/list-of-hardmod-installers-by-region.414224/
Apart from that, you either wait for a downgrade option to be available on firmware 11.0, or you buy a Sky3DS+
A Sky3DS+ can only do .3ds roms, and you need a private header to play online, and you are limited to retail cartridge releases only. You'll need homebrew access to even consider playing out-of-region games on it. Which, I guess on an NA or EUR console, you'd just get the Freakyforms Deluxe .3ds rom and get that setup.
But anyways, those are basically your options on 11.0.0-33