To access the new chart data api, you will need to reference the T4ChartDataAPI.40.dll in your project, in addition to the other references listed at the beginning of the document.
The new functionality is located in the namespace T4.API.ChartData. The indicator studies are located in the namespace T4.API.ChartData.Indicator.
' Import the T4 definitions namespace.
Imports T4
' Import the API namespace.
Imports T4.API
' Import the API.ChartData namespace.
Imports T4.API.ChartData
' Import the API.ChartData.Indicator namespace.
Imports T4.API.ChartData.Indicator