An early exit requires separating three figures: the bank's remaining share, any outstanding fees or amounts due up to the exit date, and the costs of transferring or selling the property.
Request a written settlement scenario, as summing the remaining installments may yield a misleading figure if the installments include both share purchases and fees.
The figures, fees and limits in this answer vary by bank and change over time — confirm them with your bank or the official source before acting.