Chances are very low in the US, but if you've got an early rev 4.0 A2000 model (A1000 chipset) there's no way to upgrade to ECS. Check whether yours has a square PLCC Agnus to make sure.
To change the 512 KB chip & 512 KB 'slowfast' setup to 1 MB chip with an ECS Agnus, you need to change jumpers J101 (moves 2nd 512 K down) and J500 (disables $C00000 mem).
