bushnell trailsentry camera modification to circuit

[tgrasshopper]

Hi all,
I'm new here, not sure if any one can help me with this?

I have a bushnell trailsentry camera.
http://www.bushnell.com/trailcameras/trailcameras_trailsentry_11-9204.cfm
I'd like to modify the way the camera get it's power.

Camera use 4 D Cell.

I'd like to change this for a dry 6V square batery.
I'd also like to be eable to conect a Solar Panel to the batery.

How do I do this?
I don't know muth regarding electronic circuit but i'm sure this is posible.

I had in mind to link each 4 D batery togeter and keep one + and one - conect the dry 6V batery to it.

Would this work?

Also I'd like to conect a cheap 12V solar panel to the batery how do I conect a 12V solar panel to a 6V dry batery?

THANKS ALL