Install Constant Care Admin via the NuGet Package Manager on the Kentico admin site/project.
Be sure to use the correct version (based on YOUR version of Kentico):
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.KX13
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.K12
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.K11
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.K10
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.K9
Install-Package BizStream.KenticoToolkit.ConstantCare.Admin.K82