If you need a detailed installation process, please read here.
Please note that the package had been renamed from cds-indico to indico. Make sure you delete the old .egg file before installing.
If you prefer to download the egg or tarball to install manually:
python /path/to/indico/bin/migration/migrate_0.97_0.98.py --prev-version=<version>
Replacing <version> by the version you are upgrading from (e.g. 0.97).
If you are using the Room Booking module, you should add the --with-rb parameter;
If you are upgrading from 0.97b, you should also follow the section "from v0.97b or Git Repo".
Since the new version comes with more indexes, after installing 0.97xx you will have to run the scripts:
(then proceed as if you were coming from 0.97.x)
from older versions
Check the instructions here.