It is time to put your fears to rest. They led a good life, one much longer than expected and now it is time to let them go.
Bid them a fond farewell and thank them for all they have taught you.
Allow this to be an easy transition by letting them go, otherwise it will be a long drawn out battle. The choice is yours as they know their work here is done. They are only staying because you refuse to let them go.
Trust as you release them they will transform into something beautiful which in turn transforms you.
For this is a natural cycle of life. Letting them go is just the beginning of something new. Something wondrous awaits you.