On the back of your unit there will be a block connector port. Your unit is aux compatible NOT ready. You can buy the hardware on eBay for about £16 all in. You'll need the block plug to 3.5mm female socket (about a tenner) and a simple 3.5mm to 3.5mm male patch lead (a couple of quid). You'll need to route the block plug to socket to where ever you want it. I looked earlier on eBay.

Most kits, and I have bought a few for newer shape fiesta applications, are stated as for use with the cd6000 stereo. I'm not familiar with the Sony plugs so unsure if they are the same or not. That's as far as I can help you.