Coil pack help

[omendamo]

I'm following the guide http://www.seatcupra.net/forums/showthread.php?t=141031 to change my ignition coil (misfire in #1). 

 

 

I'm getting stuck at pulling apart the plastic casing which hold the wires connected to the coil pack. I've tried with all the strength I dare use to pry these apart. I'm scared to pull any harder incase I snap the coil pack and have another issue on my hands. Is there a release I need to push in, or do I have to pull them REALLY hard? 

 

Also I'm replacing with the cheapest one I found in halfords. Is this going to be suitable or should I change to the offical part when I can?

Edited 25 November, 2013 by omendamo

[vrs777]

Pull up they are just tight!

I bought a cheap set from euro car parts that failed after about a month, replaced with their better grade

[omendamo]

Getting them out from the spark plugs hole is easy, it's prying the black connector apart which connects it to the electrics. 

[vrs777]

Oh yeah they are clipped on

[patrolman]

push the plug on further then release the tab, they can be tight against the rubber seal. 

[omendamo]

What tab is this? Maybe that's what I'm missing?