I would like to extract the coolant tank on a Focus MK2.5 without breaking or damaging the plastic holders or scratching the paint on the metalic red clips. How would you do it guys? They are very tight, tried with bare fingers, didn't work. Photos attached. Cheers. 

Can't really be done without a small amount of damage.  The least destructive way is to just pull straight upwards with your hands but it will take some force.  I've also tried putting small screwdrivers in to push the clips but tbh that caused more damage and didn't really make it any easier.  I found I could remove the engine mount without having to remove the tank though, so you may be able to get away without removing it depending on what job you're intending to do.

as tom said, just pull it upwards, its as tight as hell, doing with a properly hot engine makes it all must easier

I was swapping for a new bottle and didn't care, but no matter how rough I was nothing broke

I've detached mine at least 6 times and never broke it, although it does take a good old pull to shift it!