What to do with expired BRP

[DartmoorWitch]

Hello Guys
First, Thanks for all the help we've got in the past 3 months.
I've already got my grant letter this morning and Brp card came this afternoon, It took about 5 weeks for the result after the appointment for standard service. The visa type is the second extension for a spouse visa.
But the BRP letter didn't explain how to deal with the old/expired one. It does has an address above the brp letter which says BRP Reruns, xxxx. But at the end of the letter it says : If you have received a BRP that does not belong to you, pls return this letter and the BRP to the address above,with a short explanation. Does that mean the address is for the one you've just received not the old one.
Apart from this, nothing on the letter is related to how to deal with the old one.
Could someone help pls?

[seagul]

In my view you should send the old BRP card to same BRP returns address with recorded delivery.