We have setup an update site for hosting the last 10 snapshot versions of Preesm at https://preesm.github.io/preesm-snapshot-site/.
The procedure is similar to the one presented in our documentation.
Also, following the release 3.0.0, the DFTools repository has been archived. That means the repository is now read-only and we stop its support. All the releases are still available on our archived repository at http://preesm.insa-rennes.fr/repo/update-site-backups/.