Very well.
Here is how anyone can switch the submodule to be a particular tag:

<code>
cd yii
&#35; goto inside the submodule directory
git reset --hard refs/tags/1.1.13
&#35; Set submodule to track the tag 1.1.13
</code>

In order to update yii for future release you need to fetch the submodule from its origin and then reset its header to the another tag:
<code>
cd /your/project/root/directory
&#35; goto your project root directory (one that contains ".git" folder)
git submodule foreach git fetch origin
&#35; fetch any changes for submodules
cd yii
&#35; goto inside the submodule directory
git reset --hard refs/tags/1.1.14
&#35; Set submodule to track the new tag 1.1.14
</code>