http://3dbrew.org/wiki/Homebrew_Exploits
You can use smashbroshax, ninjhax and browserhax to get homebrew. Get the starter kit from here
https://smealum.github.io/ninjhax2/starter.zip
There you should use the menuhax installer to have a permanent entry point (Choose Type 2 Boot so it boots into homebrew every time).
(I recommend you use aureinand instead of reinand, if you want to then--v)
Get the aureinand files from
https://github.com/AuroraWright/AuReiNand/releases .
Put the 3ds, aurei folders and the .dat file inside your sd card root and, IF you want to boot into cfw every single time instead of homebrew launcher, put the contents of the boot.3dsx in the root of your sd card too.
(If not, do the same but with the reinand files which you can get from here
http://pastebin.com/m2CX4U8x you only need the reinand cfw files)