Newbie here , need direction with existing tenant :)

[John Walter]

I've been dipping SFH for about ten years and just recently bought a duplex with existing tenants , they have both been there over 2 years , one elderly , perfect tenant! Clean , pays on the dot by mail . Second tenant has always paid cash , last owner obliged . BUT... He's a slob , dirty dirty everything , recently started slow pay due to a couple new jobs . What's the best way to line him up , clean him up and direct payments thru mail ( he always wants a receipt immediately when paying ). Or is it preferable to give him 60 day notice to vacate ? Do they stop paying ?