Separating lamp holder to rewire

[chilisrool]

I'm looking to replace the cable on a lamp I bought but I am unable to separate the holder to access the connections. I have tried pushing in the black tabs to release the top but I haven't had any luck. Any advice on the best approach would be appreciated.

 

[littlespark]

Does it need rewired?
Is there space in the wooden base for a couple of connectors?

 

[chilisrool]

Does it need rewired?
Is there space in the wooden base for a couple of connectors?

That isn't the base; it is a floor lamp, I had detached the legs. It does need rewiring.