1) Upload all of Twitter into the Hive Mind.
2) One word: bacon. They can't have any until they stop assimilating people.
3) Force them to watch all of the Police Academy movies in one sitting.
4) Create a hive mind dead zone inside your house. Invite each Borg drone over, and then knife it when it least expects it. Bury the body, then repeat. (This one might take a while.)
It's up to you. Let's hear your plan to save the Federation from the menace of the Borg.