1. Create Seperate Layer for the border (in a DXF editor).
Note: I am use the Free DXF editor called "DraftSight".
2. Use ACE 3000 to perform conversion - DXF to GERBER.
3. Select Import and Export formats.
4. I am assuming DXF units are inch.
Note: Make sure to use FILL, JOIN, and DEEMBED for Metal layers.
5. Choose Gerber export options. Typically you can use the defaults.
You will now see that ACE has converted your Gerber and Filled objects...
6. Now lets export the Gerber files..
Note: ACE can also export Drill layer (from the small holes found on your metal layer).
Thats It!!! I have converted the DXF to Gerber and outputted Drill.