Remove the battery from the back slot.
Take the neck out of the body using the release tab on the back of the guitar. Most people only need to take the neck apart to fix common problems.
Remove the casing from the neck by unscrewing the six screws located on the back. Keep these in a safe place as they are very small.
Unscrew the single screw on the circuit board. This will allow you access to the two parts that usually cause problems: the contact between the neck and body and the button contacts. Be careful not to dislodge the ribbons while doing this as they are unmarked and difficult to reassemble.
Peel back the plastic coverings on each of the buttons to expose the contacts. Occasionally, dust can get underneath these and interfere with the controller's performance.
Pull the small contact up from the end of the guitar's neck to clean it. Use a small piece of soft clean cloth to do this. Also, be careful since the contact is easily bent; you may need to straighten it ensure that it makes contact with the guitar's body.