It is NOT necessary to add the layer changes manually. When you open the file directly from Bambu Studio and slice it, the layer changes will appear automatically AFTER slicing along with the prime tower.

If for whatever reason you need to add the layer changes manually, here is a guide. (These example pictures are from a DIFFERENT HueForge I created):

1. Open the file and slice it.
2. Go to the “Preview tab”

3. In the preview tab, look for the small round green slider on the right side of the screen. (Shown by the yellow arrow).

   

4. Move the slider to the layers listed above.

5. Right click on the slider when it´s on the correct layer and a small menu will pop up.

   

6. Select “Change Filament”
7. Select the filament you would like to choose

8. Slice again after adding all filament swaps.

   

How to add a pause in case you need it:

1. Slice the file
2. Go to the “Preview” tab
3. Right click on the green slider (when it is NOT on top of a layer change)
4. If there is a layer change at the layer that you need to add the pause, delete it
5. Right click “Add pause”