Darius if you want bold change you need to be bold like Verizon, Ford, GM, GE, UA, UTX, IBM and other real companies
Offer an incentive to leave. How about 2 weeks of severance per year of service up to 2 years of pay
Offer to add 8 weeks to your pension calc for years of service and age for every year of service
Offer to wipe out the age penalty for you and spouse if you are over 55 for starting pension early
You want to get rid of old "useless" employees over 50, then offer something and I bet you'd get all the volunteers you need. If you offer just the standard severance why bother volunteering unless you are 65 years old?