The Honda Dylan battery sits between the front wall of the underseat helmet bay and the front bodywork immediately below the front of the seat. To get to it, you will need to remove the external bodywork shroud that wraps around both sides to meet the bodywork under the seat. The shroud itself is seat coloured, not bodywork coloured. There is no need to dismantle anything inside the helmet bay.
To remove the shroud, undo the two holding bolts (one at the top and one at the bottom) in the front centre of the shroud.
Lifting the seat will reveal a black plastic pop-stud on each side which holds the shroud to the bodywork - just twist a screwdriver under the outer head to pop them.
The shroud now needs to be prised upwards from the base with a screwdriver. When the base is free, it can be worked forward - the top can be pushed from inside the helmet bay, but the seat will have to be dropped before it comes out all the way.
Good luck with that
Garth47, February 2008