Diff Lock on a 2000 Disco 2 TD5 Help?

Hi all, I live in Cape Town South Africa and last week bought a TD5 Disco 2 2000 model with 220 000 kms on. The vehicle is in showroom condition, inside and out. I spoke to the previous owner and he went once off road with it. The vehicle has a full service history with Land Rover Welkom Free State. Over the last two years the vehicle has had a new alternator, new radiator, larger intercooler with fan, new turbo, new water pump, new loom, rear seal on transfer box, new discs front and back 5 months ago) fitted. All are genuine land rover parts.
The vehicle does not leak a drop of oil either. In short, the vehicle was serviced every 10000kms and is mechanically perfect and well maintained.
Can someone help with me wanting to fit a Diff Lock lever to the drivers side wall?
I climbed under the vehicle to try and feel for the spigot and couldnt seem to find it. How do I go about fitting the lever, can any one help?
Paul +27735336155

if there isnt a spigot ,you will have to remove transfer box and change front housing and some internals ,front housing would have to have front diff bearing reshimmed as all housings vary slightly