If I am about to retire, can I get my new PCS orders changed to my last duty station where I left my family?

No you can't change your orders because you plan to retire. If you had 19.5 years at the point you were notified you could retire in lieu of PCS. You'll have to comply with the assignment instructions and either move your family or not.

One thing you might want to try is to ask your branch manager if they'd be willing to cancel your orders and FSTE you long enough to retire in place. It's almost impossible these days to get your orders switched with the enlisted Marketplace. Once your assignment is generated it is out of the hands of your branch manager. But, the branch chief might be capable of supporting you staying in place for one more year and deleting your current assignment. You would still be away from your family, but you wouldn't have to move them or come out of pocket for a second residence

Apply for a hardship.

I feel like the Army might say "fuck your plans." But you can talk to your assignments manager and see what they might be able to do or tell you.