Who or what is asking you to "use" the Home Sale Worksheet? What are you trying to do?
In TurboTax Online you cannot access the worksheets directly. Everything has to be entered in the question-and-answer interview. Follow the instructions that DoninGA gave you above.
Even if you are using the CD/Download TurboTax software, you should enter the sale of your home through the interview. Using the worksheet is complicated and likely to lead to errors.
