mk2 octy , my passenger dead locked door

so this has happened and i know its popular on the mk1, but i cant figure out this search functions on here. if anyone has any info pls can they direct me. its the passenger door, its deadlocked, ive torn off  the card and revealed all the gubbins underneath. am i correct in thinking i need to drill out the rivets and take off the inner metal card , to gain access to the door lock itself? i have ordered a new lock already.

when i press the door lock button i can feel the bits inside moving around, so i know something is moving, but pulling on the handle does nothing. i have tried pulling and leaning and pressing and forcing but to no avail.

any help from you would be great

Dan