How to change Assembly Version Number using AssemblyInfoTask?

I am trying to automate the process for setting the Version for all DLL's, after spending some time I came to know the AssemblyInfo Task with which it can most likely be achieved.

So I went ahead and installed it, specifically version 1.0.51130.0.

After Installing, I manually added the Import Tag (by unloading the each project) of AssemblyInfoTask in .cspoj files (the solution has more than 35 proj files).

<Import Project="$(MSBuildExtensionsPath)\Microsoft\AssemblyInfoTask\Microsoft.VersionNumber.Targets"/>

Next I modified the Microsoft.VersionNUmber.Target file which will be installed in path: C:\Program Files\MSBuild\Microsoft\AssemblyInfoTask, and I modified the following section:

<!-- Properties for controlling the Assembly Version -->
<PropertyGroup>
    <AssemblyMajorVersion>4</AssemblyMajorVersion>
    <AssemblyMinorVersion>0</AssemblyMinorVersion>
    <AssemblyBuildNumber></AssemblyBuildNumber>
    <AssemblyRevision></AssemblyRevision>
    <AssemblyBuildNumberType>DateString</AssemblyBuildNumberType>
    <AssemblyBuildNumberFormat>01MMdd</AssemblyBuildNumberFormat>
    <AssemblyRevisionType>AutoIncrement</AssemblyRevisionType>
    <AssemblyRevisionFormat>00</AssemblyRevisionFormat>
</PropertyGroup>

<!-- Properties for controlling the Assembly File Version -->  
<PropertyGroup>
    <AssemblyFileMajorVersion>4</AssemblyFileMajorVersion>
    <AssemblyFileMinorVersion>0</AssemblyFileMinorVersion>
    <AssemblyFileBuildNumber></AssemblyFileBuildNumber>
    <AssemblyFileRevision></AssemblyFileRevision>
    <AssemblyFileBuildNumberType>DateString</AssemblyFileBuildNumberType>
    <AssemblyFileBuildNumberFormat