98-How to unlock from inside?

Just purchased a 98 ml320 with no owner's manual. I'm still trying to figure out how to unlock the doors from INSIDE the vehicle. I can take the key out and use the remote. The central lock switch on the console will lock all, but not unlock any. What am I not doing right?

Also, can anyone direct me to a pdf or other online source for an owner's manual?

THANKS