The EVO1-3 ECU is designed to pass only 32KB of EPROM space to the processor. ECMLink includes enough code modifications that more space is needed than that. Luckily, the Mitsubishi ECU engineers were kind enough to provide a simple jumper modification to allow for this.
To enable the full 64KB of EPROM space on an EVO1-3 ECU, you simply have to move a jumper from one spot to another. Unfortunately, this jumper is soldered to the board. So it's not quite as simple as the "typical" jumper move you may be familiar with on PCs and such, but it's not hard either.
The image below illustrates the location of this jumper and what change you need to make.
To perform this move, you simply desolder the 0 ohm resistor installed at J2 and solder it into place at J1. It's easiest to do this with two soldering irons, but you can make due with 1 if you have to.
If you have two soldering irons, heat each up and gently touch one to each side of the resistor at the same time. This will free the component from its spot. Then simply solder into place at J1.
If you only have one soldering iron, then you may want to use some solder braid or some form of solder sucker to work on each side individually. It's really not hard and anyone that could do the socket job originally can easily move this jumper as well.
Another, less desirable option, would be to either break the resistor or cut the track leading from the resistor to ground and then solder a simple wire across J1 instead. It's certainly an option, but probably not the one I'd personally recommend. It could be quicker and easier, but it can also do more damage than good if you are not REALLY careful.
NOTE: Your original factory EPROM should still work fine after this modification has been performed.
Here's a shot after the jumper has been moved.