...
- Remove all users but your own from the project
- Delete all heat stacks
- Deattach and delete all volumes
- Delete all virtual machines
- Delete all ports
- Delete all firewall-rules
- Delete all firewall-policies
- Delete all firewalls
- Delete all routers
- Delete all subnets
- Delete all networks
- Delete all security groups
- Delete all floating IP's
- Remove your user from the project
- Delete the project
...