I have a Freelander 2 2007 HSE which has developed faults as below

When locking the vehicle I push the lock button once on the remote, lights flash as per norm.

when dead locking the doors by pushing the lock button a second time lights don't flash a second time interior lights don't come on and one door remains unlocked.

Have been advised that replacing the door switch would be the answer but is this a difficult job or could a bit of grease be the answer? if not is removing the door card a difficult task?

Thanks a bundle for any insight into my problem!

It's likely to be the door lock actuator that's the problem, which contains the lock motors, and door closed sensor. 2009 Rimini Red SE TD4. Soon to be sold.
Hyundai Ionic 5 Ultimate on order.
Gone. 2006 Tonga Green i6 HSE.

Door card removal
 Every time I learn something new,something old gets pushed out of my brain?