(Excuse me for the general reference I gave you earlier.)
A bit more specific:
* Change ./debian/source/format into "3.0 (quilt)"
* Change "(0.4.0)" into "(0.4.0-1)" in the first line of ./debian/changelog
* Remove the ./debian directory from your source package (as per
What.27s_wrong_with_upstream_shipping_a_debian.2F_directory.3F).
* Upload both the adjusted original package and the debian package.
Best wishes,
Guido van Steen