1. Create the sheetmetal part.
2. Create the mold tool using solid modeling tools.
3. Click Insert --> Sheet Metal --> Forming Tool and specify the stopping face and faces to remove.
4. Save the part as a Form Tool type (*.sldftp), in the "save as type" pulldown menu.
5. Open your sheetmetal part.
6. Open the Design Library, then click the "Add File Location" button at the top.
7. Select the directory where you saved the form tool. That directory should appear in the Design Library.
8. Click the new directory. You should see thumbnails of all the files in it. Select the form tool and drag it onto the sheet metal face you want to indent. A popup will appear; click Finish.
9. The new form tool will appear in the FeatureManager Design Tree. Open its sketch. Use dimensions & relations to position the form tool.
Hope that helps.