Renter's rights question?

My husband and I are currently renting. The garbage disposal is broken. We talked to our landlords about this and they said they would reimburse us for a new one but would not pay for the labor to install it. My husband has done a lot of work on this house for reduction in rent but he does not know how to install a garbage disposal, so we would have to hire someone. Is my landlord being unfair? It brokeout of normal wear and tear. My feeling is the garbage disposal should be treated like the dishwasher, etc. Thanks!