1977 280SE front headrest

Dumb question, but driving me batty!

I've got myself a very neat & tidy 280SE and
want to remove/wash the original seat covers.

Cannot for the life of me work out how to remove
the headrests from the front buckets seats and don't
want to damage anything 'cause she's immaculate.

Any ideas?

Would appreciate the help, tried on line user manuals
but they only cover the newer headrests.

Thanks for your time.