This is taken from one of the miscellaneous docs I've been reading, not sure where it's from or who originally wrote it:
Find Jumper J101 located on the lower right side of the power connector CN400, and consists of 3 posts - 2 of the posts are shorted together using a shorting block. Remove the shorting block and move it to the left, towards the power connector. For further info, see Page 13 of the A2000 system schematics - this jumper will enable address line 19 from the 68000 which controls the 1 meg address range.
Locate and cut Jumper pad J500 (to the lower left of the 8520 at U301). This is a 2-pad jumper with a trace connecting the two pads. See Page 9 of the A2000 system schematics - cutting this trace keeps the _EXRAM signal from being tied to ground.
To enable PAL rather than NTSC - locate and cut J102, NOT J201 as suggested in some docs. This is the equivalent of bending pin 41 of Agnes in the A500 mod.