It's not that bad a job, done the right way. I thought there was a guide written by me, but I can't find it now.
Basically, you do it as follows:
1. Remove the power steering fluid reservoir; unclamp it from its bracket, drain the fluid and place it to one side;
2. Unclamp the hydraulic hoses from the bulkhead;
3. Loosen the outside nut clamping the ABS block;
4. Remove the inside nut clamping the ABS block, the bend out the steel plate to allow the ABS block to be raised;
5. With a long screwdriver, engage the purple locking arm holding the multiconnector in the ABS block, pull it to unlock;
6. Wriggle out the multiconnector;
7. Grasp the ABS block firmly and lift it up, bending the hydraulic pipes, until the ABS ECU is high enough to reveal all 6 mounting crews;
8. Support ABS in this position with a block of wood or similar;
9. Undo the 6 screws, unplug the cable at the bottom;
10. Remove ABS ECU.
Replacement is the reverse of removal.