[danzvtil]

Your best bet is to make an unsolicited offer thru the managing agent, but ultimately you can't buy what's not for sale.
The owner doesn't want to move these tenants on because it will cost them money (approximately 2.2weeks rent plus advertising fees plus any refurbishment costs), you could try to offer via the agent some cash to cover that cost.
But I sympathize, our system allows disfunctional members of society to harass and spill over onto other people in the neighbourhood.