NOTE: A.C.E. has been kind enough to make an instructable on this topic already. This instructable is meant to address problems and updates to the software. Also I did not write The Ghost, see The Ghost's official page here.
DISCLAIMER: AS WITH ALL WII HOMEBREW, BE CAREFUL WITH WHAT YOU DO TO YOUR WII. I AM NOT IN ANY WAY, SHAPE OR FORM RESPONSIBLE FOR YOUR WII. ALSO, COPYING WII GAMES IS ILLEGAL. NUFF SAID. PERIOD.
Well, now that that's out of the way, let's get started!
Step 1: Before We Begin
Step 2: Parts List
+ A Guitar Hero 3 or Aerosmith .iso file
+ XP-codec pack
+ 2 to 4 GB (or more) of free disk space
For those who don't know, The Ghost comes as a .rar compressed file. I know that links die, so after a while you may need to just search Google for the .rar file. But for now, get it here or go to the Ghost's homepage as shown on the Intro page of this instructable.
You will need 7-zip (which is free) or another program that can decompress .rar files like WinZip to open "TheGhost.rar" Get 7-zip here. Go for the first or second .exe file, and then install it.
Ah, the .iso. Again, this must be obtained legally!!! You can get the actual .iso file from your very own Wii and not by torrents by following the wonderful guide by thundaboy here (also on the intro page). After reading his guide, you can extract the actual .iso from an external hard drive or flash drive with WFBS Manager. Ask him for help with this, not me.
The XP-Codec Pack is strictly for The Ghost, and is probably the easiest to get. A codec is a small file
stored in C:\WINDOWS that lets your computer play and make music and video files. In this case, we need to be able to handle .ogg .wav, and xbadpcm files. Get it here, and then install it.
Finally, you need a good amount of disk space to run The Ghost. It manipulates song packs, reads data partitions, deletes video cores, converts audio, etc. and needs a good deal of temporary space to do this.
Once you have installed the XP-Codec Pack and have the .iso file, you can move on.
Step 3: Get Some Frets On Fire (Fof) Songs
Each song comes in the form of a folder, containing a song.ini, notes.midi, song.midi, and one or two other things. In reality, each song may not have everything or have the three things listed above in different forms, but don't worry, unless the song is corrupted or broken it will still probably work.
Make an account at Fof here, and grab songs from the Fof song wiki. (See image below)
NOTE: At the time of writing, it seems that the site is down. You can go to the wiki, but all the links are broken. Try this instead, or just google "frets on fire songs".
No matter how you do it, once you have a few songs, unzip them with 7-zip (or whatever you used before) and put them somewhere on your desktop, or wherever you like. The only thing that matters is that you know where they are. After that, you can get started with The Ghost.
Step 4: Set up and Verify The Ghost Files
And then in tool, three important files:
If these files are not there, the .rar file you downloaded was corrupt or broken. Try to get it somewhere else by searching "Guitar Hero Custom The Ghost" in Google.
Step 5: Check Codecs
One of three things will happen:
1. You hear the sound, answer yes, hear more sounds, and four green check marks appear. In this situation, you're great! Head right on to Part 2.
2. You hear the sound, answer yes, but hear nothing else. There is one green check mark, but three red X's. This most likely means that XP-Codec pack is not working. In that case, go to the next step.
3. You hear nothing and four red X's show up. Oddly enough, this is better than option two. Most likely, it is actually TheGhostAudioTool.exe that's wrong, so your best bet is just to keep going to Part 2. On the other hand, if you can't play mp3 files, then you've got a problem. Go to the next step.
NOTE: If there are any other possibilities (besides the three above) please send me a message.
Step 6: Debug
If the first check mark did not go green and you can't play mp3 files on your computer, we need to fix that. Go here and hit download, right in the middle of the page.