Hello all, first post so my apologies for what could be an easy fix but I'm not a mechanic so please go easy on me.

I've had a Focus 1.8 TDCi hatchback sat in a garage for 3 years waiting to be converted to Spanish plates with a 1/4 of a tank of diesel in it. I realise now I shouldn't have just left it like that but from what I've read, the fuel has gone bad and needs to come out. I've tried syphoning it but all methods on YouTube have failed. I've looked under the back seats but can't get access to the pump to syphon it that way and I tried disconnecting a fuel line, turning the ignition switch a couple of notches but that didn't produce any fuel either. I’ve read quite a few people saying that this method works but they all assumed the person reading knew where about to disconnect the fuel line. I have attached a photo of where I disconnected the line as there is a nice easy joint but I’m guessing this may not be the right place to do it?

So in a nutshell, what’s the best way to drain ¼ of a tank of diesel and if it is by disconnecting a fuel line at the engine and turning the ignition on and off, where about do I disconnect it?

PS I’ve changed the battery and the oil (and filter) but I’m a little hesitant about changing fuel filters as I’ve read too many posts about cars not starting because of air in the system and not being primed and then I start to feel out of my depth so was hoping to just remove the fuel and then let the garage change the fuel filter and air filters (haven’t even looked into that yet) and whatever else should be changed after sitting for 3 years.