Need advice, before I make bigger damage.

The sparks on my Octavia MK3 77KW 2013, CJZA, are not regulary changed, so the rubber, cable or the contacts are "sealed". Spark plug cabble cannot be detached,

 

Any help is appriciated.

 

Best advise I've had is to really heat the engine up before trying to remove the cables. 

 

It's not the best design sadly so there is a chance of damaging the cables or connections to the spark plug. 

 

The mechanic I used was able to remove mine ok after getting the engine temperature right up before attempting to unplug. 

You need a special puller to get the coil packs out. Known problem, and even with the correct tool it's easy to break the coil packs and sleeving.