Under Notifiers from the Project Information page, click Add.
On the Add Notifier form select IRC from the pull-down menu and click Submit.
On the next page, fill out the form with the following information:
IRC Host
IRC Port
IRC Channel
Nick Name
Alternate Nick Name
User Name
Full Name
Password which can be left blank if you did not specify one in your IRC account
Select the Send on ... options you want.
Click Save. The IRC notifier you just added will be listed under Notifiers on the Project Information page along with the other notifiers you may have set up prior to this.