1. PN4000 online help
2. CAD
3. File
4. DXF Import
5. ME10
6. Layer dialogue box

Layer dialogue box

Retain all layers:

Here, you select that all layers are to be retained.

Retain selected layers:

Here, you select that all selected layers are retained.

Delete selected layers:

Here, you select to delete all selected layers.

Select layer:

Here, all layers are listed and can be activated.