You have to unclip all the switches first. Take the headunit out also.
Once all these are out of the way you will find a few screws (about 5-6) located behind the switches. This will be clear once you have taken the parts out.
There are 2 screws near the top of the speedo and one behind the main light switch.
Pull the dash surround out and there will be 2 more screws that old the speedo in place
Pull the speedo out but try and keep the speedo cable in its place. Refit the hose and your done mate.
The hose probably came off if it was pulled from the inlet manifold