You can't access Form 8949 directly. You must go to the home sale you entered and edit it that way.

When you enter your sales or exchanges of capital assets in TurboTax Premier or Home & Business editions, we automatically fill out Form 8949 for you.  

To find Form 8949 follow these steps below: 

To enter sales or exchanges of capital assets, 

1.  At the upper right corner, in the search box, enter investment sales and click the Jump to investment sales link.

2.  On the screen Did You Sell Any Investments in 2017?  click Yes and answer the interviews to enter your investment sales information.

3.  Once you find the home sale, you can click edit beside it.