Ok: You have 1.8.0 working so I can shorten the instructions.
1) download akAIO 1.8.1
2) Extract and rename the akmenu4.nds to akmenu.nds also make another copy of this file and rename to akaio.aio
3) Put the files you just made, akmenu.nds and akaio.aio, and the /_aio folder onto the root of the SD card
4) download DScovered
5) place the files akmenu4.nds, dscovered.nds and the /d_system folder from the \DS folder in the DScovered archive to the root of your SD card. (you should already have this)
6) download moonshell2, I like the Child Zwai Edition but its up to you which one you use.
7) Run the auto extract and the copy the extracted moonshl2.nds and /moonshl2 directory to the root of your SD.
8) download Xenon++ archive
9) copy the files from the /moonshl2 and /d_system folders in the archive to exactly the same locations on your SD card. Replace files if needed, extlink.dat should be the only file that asks to be replaced. (you will not need anything else from this archive)
10) Run dscovery.exe from the PC. Make sure you choose akmenu.nds and moonshl2.nds before you update the card as this will give you access to akmenu and moonshell from the coverflow. You can also update the covers for these two files, I have included covers at the bottom of this post it is also a good idea to double click and rename them or they will show up as . in the coverflow.
11) Run up the DS. Go to options and change the loader to loader_extlink.
12) Everything should now work. Just remember if you want to run akmenu hold down the B key or it will get stuck in a loop.