The takeover itself was led by Rov who was aided by inside help from Vark, the supervisor of the kitchen staff at the embassy who was able to have fifteen members of Klahb hired in the month prior to the takeover.
The goal was to take control of the embassy and use its staff as hostages for bargaining. Rov, speaking for Klahb, contacted the Klingon High Council and demanded that Martok step down as Chancellor, that the hologram impersonating Kahless be deactivated, and that Empire declare war on the Federation.
Eventually, the takeover was ended when Worf was able to regain control of the security system and flood the building with anesthizine gas knocking everyone unconscious. Rov was able to escape in the confusion, but the rest of the surviving Klahb members were captured, held, and later executed by the Klingon authorities. Rov later turned up broadcasting his demands to the entire empire from Pheben V. The base was destroyed by a Klingon fleet patrolling the nearby area; however, Rov was likely using some sort of remote transmission device as his body was not recovered. (TNG novel: A Time for War, A Time for Peace)