1) Run yuzu_install.exe   (or goto https://yuzu-emu.org/downloads/ and download the latest version)
2) Launch yuzu for the first time  (it will complain that keys and firmware are missing)
3) Close yuzu
4) Open Windows File Explorer and type the following in the address bar:

%appdata%\yuzu\keys

5) Copy the prod.keys file from this folder into the yuzu\keys folder
6) type the following in the address bar:

%appdata%\yuzu\nand\system\Contents\registered

7) Copy all of the contents from the 'Firmware 11.0.0' folder into the yuzu\nand\system\Contents\registered folder
8) You can close the Windows File Explorer
9) Launch yuzu again

10) Click Menu > File > Install Files to NAND...
11) Select the v0   version of  Makai Senki Disgaea 6 [0100307011D80000][v0][JP].nsp   then click Open  (base game)
12) Wait for the install to complete
13) Click Menu > File > Install Files to NAND...
14) Select the v458752  version of  Makai Senki Disgaea 6 [0100307011D80800][v458752][JP].nsp   then click Open   (patch 1.1.1)

15) Disgaea 6 is installed and ready to launch... 

Other Settings:

16) Click  Menu > Emulation > Configure...
17) Select 'Graphics' from the left list box
18) Change the API from 'OpenGL' to 'Vulkan'  (if your computer supports it)

19) Select 'Controls' from the left list box
20) Change 'Input Device' from Keyboard/Mouse to your controller
21) You might need to adjust the control buttons here
22) Click OK when finished