Inheriting an underpaying tenant in California

[Brian Sherman]

Found a great duplex in a great location for an amazing price. Only problem (and the reason it's such a deal), there's a tenant that's lived there for 20 yrs who is paying really low rent with a 2 yr lease (though it's got about 1.5 yrs left). He's kind of a hoarder and said that he hurt his back and doesn't really want to move because of the injury. I'm in California, where the laws suck for landlords. Should I get into contract? When the lease finally ends, am I going to have a problem getting him out because he is somewhat disabled? On the plus side, he's never missed a rent payment and seems very nice. Am I a total sucker?