What is a recommended protocol for detoxing a 70 year old female with diabetes, htn, and cardiac history from ativan (lorazepam) 1mg tid taken for 40 years?

Consult Psych/ We know this has to be done slowly. The question is tapering off or reducing the dose from 1 mg tid to 0.5 mg tid x 1 week, then to 0.5 mg bid to 0.5 mg qd in another week to 0.5 mg qod another week, then to 0.5 mg twice a week, then 0.5 mg once a week, or more gradual every two weeks make the changes. Your best bet is to consult with a psychiatrist or substance abuse specialist to supervise her.
Very slowly. It would likely take months to do this safely as an outpatient.