Hi mate , to take the tank off fully you have to disconnect the speedo housing completly which is a simple job, the housing has two black push in fasteners at the front , just push the middle bit in with a little screwdriver or something and they will pop out then undo the screw holding the main bit on , then you can lift off the housing to get underneath it , you will see that the speedo cable is just unscrewed from its socket underneath the housing (by this I mean with your thumbs , not a screwdriver ) and there is two electric cables to unclip and the tank breather pipe to pull off , then the tank will be clear to remove.