To get the data of the WebOffice Sample Project, copy the folder WebOffice10.2-DVD\SampleProject\Data from the DVD to your preferred data directory (e.g. D:\Data\SampleProject\).
In a next step copy the content from the folder WebOffice10.2-DVD\SampleProject\WebOffice directories Add-On\ServiceDocuments into your ServiceDocuments directory (e.g. <ArcGIS Server location>\directories\ServiceDocuments). First check now if the copied MXDs are set to Read-only. In case the files are set to read-only, deactivate the checkbox.

Allow write access to the MXDs
When opening the MXDs there might not be found any data due to the change of the directory structure. In this case open SampleProject_Cadaster.mxd, double-click the first layer and activate the Source tab. There you will find the name of the Feature Dataset and the Feature Class which you have to look for when repairing the data source. Do not repair the data source by clicking Set Data Source... in the layer properties because this way all data sources would have to be set manually.

Check the name of the feature dataset and the feature class of the layer before repairing the data source
Instead, close the layer properties and right-click on the same first layer and go to Data > Repair Data Source...
Browse to the location for your data directory containing the data of the WebOffice Sample Project and select the correct feature class.

Repair all data sources at once
This way all data sources are repaired at once and you can save the MXD by clicking File > Save As... Then repeat this step for all the MXDs of the Sample Project in the same way in order to proceed to next step.