Fitting aftermarket radio

[McQuaid]

Hi all

Well, I'm looking to fit a Sony radio into my Boxster, was told by guy in shop it would be straight forward plug and play etc, well, it's not

Porsche radio out, have one black connector and one small yellow one, the wiring that came with sony will only take one of the black connectors, I have no where to connect the yellow block into and these appear to be speakers as I'm getting power but no sound, any know if there is a certain harness adapter i need or am i missing something? Obviously I don't really want to slice the wires etc but I will if i have to

Also, do I need to do anything with alarm? It appears there is something fir alarm on the old radio's frame, any ideas?

Thanks all