Special tools required to remove the springs

Well I went out this afternoon on this lovely day to get stuck into swapping over the springs in my Octavia but quickly discovered that my spline bit set only goes to M12 and I assume that the bolts holding the shock on are M14. Nowhere in my local area has anything bigger than M12 in stock at the moment so I've had to order it off the internet so my springs will have to wait till the weekend now probably provided the weather holds out.

My question is, though, am I likely to come across any other "specialist" tools to do this job? I have a brand new set of Draper spring compressors ready and waiting to go.

Also - has anyone got any hints and tips on changing the springs on the Mk2 Octavia??