Teeth grinding normally has a neurological and psychological etiology.Since he is 83, it's pretty normal to see a certain level of tooth wear and sensitivity.
However, without seeing the patient clinically,it's not justified to make a treatment plan, still to answer your question; No, extractions cannot be done at home, especially for a medically compromised patient.
Before proceeding for extractions,the dentist normally asks for blood picture and cardiologist opinion (if he is on aspirin).
Next Steps
Visit a local dentist.Explain your problems and chalk out a treatment plan.
Since he is bed-ridden,click pictures of the entire oral cavity, individual tooth and take along all of his medical reports for the first visit.