A 68-year-old male with COPD GOLD Stage IV presents to the ICU with acute exacerbation and type II respiratory failure (pH 7.28, PaCO₂ 65 mmHg, PaO₂ 55 mmHg on FiO₂ 0.6). He is intubated with an endotracheal tube (ETT) and started on mechanical ventilation. After 10 days of mechanical ventilation, the patient remains ventilator-dependent with weak spontaneous breathing efforts and copious secretions. His consciousness is alert and oriented. What is the most appropriate next step in management?