To use this overlay you first need to configure layman. Once
you have don this, copy the included overlay.xml file over
to /etc/layman/overlays/sdaps.xml so that layman knows about
this overlay.

After this you can active the "sdaps" repository using
 $ layman -a sdaps

Then you can update the repository using
 $ layman -s sdaps

Once the above steps are done, it is possible to install
SDAPS using the normal gentoo method:
 $ emerge sdaps

Have fun!