Notice to quit - strategies for smooth transition

[Dennis Meints]

I'm looking to send a 'notice to quit' to a tenant that's been in conflict with lease terms on several different points (unlawful possession of firearms, not maintaining clean unit, disturbing other tenants right to quiet enjoyment of property, etc). My lawyers say we could file eviction, but it's likely going to be a long road to enforce the eviction without a lot of supporting evidence other than "he said, she said" and anecdotal evidence. 

We'd like to part ways with this tenant and make it an easy decision for them to leave. What strategies have you used to motivate tenants to quit the lease and move on?