Update:
It appears AEM has discontinued manufacturing these big brake kits and replacement rotors. Power Performance Group (powerslot rotors) aquired AEM's big rotor brake line of products. It looks like these kits no longer come with the 2 piece rotors and are now called the Power Slot Plus System. You can find them at The Tire Rack.

The pre 93 1g Talon/Eclipse/Lasers came with waaaay undersized brakes for the weight and amount of power these cars could make. Upgrading the single piston calipers to the dual piston calipers that came on the 93+ and 2g AWD cars is a cheap upgrade that greatly improves braking (I think the V6 Y2k Eclipse and non-turbo 3000GT/Stealths also came with the dual piston calipers). Throwing in some AEM big rotors makes it even better. Throw in some Porterfield R4-E pads and life is grand :) Of course they're not as good as the Stoptechs, but they're a good bang for the buck.

Here's the walkthrough of the 2g caliper conversion + AEM rotor install my brother and I did on his car (92 Eclipse GSX). We each did one side to save time.

Pic of the stock 1g single piston caliper and puny little rotor:

First thing to do is remove the brake line from the stock caliper. By the way, you might as well swap out the stock rubber brake lines for some stainless steel brake lines while you're at it:

Next remove the caliper and rotor:

If the rotor is rusted on, you can push it off by torquing a screw into that little hole on the rotor. Or, if you can't find the right sized screw, spray it down with some WD-40 and tap the rotor with a hammer to break it loose:

Beat the crap out of it with a hammer if the damn thing still won't budge:

Now that you've shown the rotor who's boss, the next thing to do is cut the dust shield (or whatever it is) off:

Install the bracket that came with the AEM rotor to extend the caliper out:

Before installing the AEM rotor, pound the lip that sticks out on the lower ball joint down with a big hammer. Otherwise it'll rub and grind when you turn:

Comparison pic of AEM rotor vs stock rotor:

Install the AEM rotor:

Install the dual piston caliper, brake line, and brake pad:

All done!

Update:
Stay away from cross drilled (x-drilled) rotors if at all possible. The cross drilling doesn't really do jack besides crack once you really use the brakes hard (eg. track days, auto-x etc):

I've since moved to using slotted rotors and they've held up pretty well even under the abuse of the Porterfield R4-E race pads