Steps to delete  the training  Sites and uninstall the whole thing

Microsoft Office sharepoint  Server 2007 Training consists of four
sites: Home, Administrator, Report, and Learner site.

Caution: The sites must be deleted in the following order: Learner
Site, Report Site, Administrator Site, and finally the Home Site.

1. Open Internet Explorer and go to the Microsoft Office
SharePoint Server 2007 Training Home site.
2. Click the site  Actions > Site Settings.

3. On the Site Settings page, under the Site Administration
column, click the Sites and workspaces link.

Delete the Learner Site

1. Delete the Learner Site by clicking the in the Delete
column next to Learner Site.
2. Click the Delete button.
3. Click the OK button on the confirmation dialog.

Delete the Report Site

1. Delete the Report Site by clicking the in the Delete column
next to Report Site.
2. Click the Delete button.
3. Click the OK button on the confirmation dialog.

Delete Administrator Site

1. Delete the Administrator Site by clicking the in the Delete
column next to Administrator Site.
2. Click the Delete button.
3. Click the OK button on the confirmation dialog.

Delete the Home Site

1. Delete the Home Site by clicking the Site Actions > Site
Settings link.
2. Under the Site Administration column, click the Delete this
site link.
3. Click the Delete button to complete the Delete.
4. Click the OK button on the confirmation dialog.
5. All the sites have been deleted when you see the screenshot
below:

Retract and Remove Solution

Follow the steps below to retract and remove The Microsoft Office
SharePoint Server 2007 Training from your SharePoint environment.

1. Navigate to the Central Administration page.
2. Under the Global Configuration column, click the Solution
management link.
3. Click the mosstraining.wsp link.
4. Click the Retract Solution link.
5. Click the OK button. Retracting takes a few minutes.
6. Refresh the page until Status is Not Deployed.

The Microsoft Office SharePoint Server 2007 Training is now retracted
from your SharePoint environment.

Remove the solution

1. Click the mosstraining.wsp link.
2. Click the Remove Solution link and click OK button on the
confirmation dialog.


The Microsoft Office SharePoint Server 2007 Training is now removed
from your SharePoint environment.

Uninstall

Uninstalling Microsoft Office SharePoint Server 2007 Training will
remove the program on the server.

1. Open the Add/Remove Programs, Start  Control Panel 
Add/Remove Programs.
2. Click Microsoft Office SharePoint Server 2007 Training.
Click the Remove button, or if you are using a Windows Vista™
operating system, click Uninstall at the top of the screen.
3. Click the Yes button on the confirmation dialog.

The Microsoft Office SharePoint Server 2007 Training has been removed.