To uninstall i2p just follow these instructions.
sudo apt-get remove i2p
This will remove just the i2p package itself.
sudo apt-get remove --auto-remove i2p
This will remove the i2p package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for i2p then this will work.
sudo apt-get purge i2p
Or similarly, like this i2p
sudo apt-get purge --auto-remove i2p
|Description||I2P anonymous network applications can use to securely communicate. All data is wrapped with several layers of encryption, and the network is both distributed and dynamic, with no trusted parties.|