Changing the Terrain for an Existing Neighborhood:
One possible use of HoodReplace is to add roads or make other terrain changes to an existing neighborhood.

Requirements:

1. HoodReplace, installed.
   .
2. An SC4 file which corresponds to your existing neighborhood terrain. This file is usually found in the directory:
   ...\My Documents\EA Games\The Sims 2\SC4Terrains
   
   - If you are using a neighborhood which came with the game, then EA usually provides a corresponding SC4 file.
   
   - If you created a neighborhood from scratch, then you either selected an existing SC4 file, or you copied a custom SC4 to this directory.
   .
3. SimCity 4 / Rush Hour, or SimCity 4 Deluxe. If you don't have a copy, you might want to consider buying one; I've seen them in stores for $10 or less.

Making changes to the terrain:

1. Run SimCity 4. Create a new region called EditTheSims2 (or whatever). Exit the game.
   
   Alternatively, you can download EditTheSims2.zip (attached here) and unzip it into ...\My Documents\SimCity 4\Regions\ and then skip the next step.
   .
2. In ...\My Documents\SimCity 4\Regions\EditTheSims2, edit the config.bmp using the Windows Paint program and change it to a 1x1 (pixel) BMP. Change the color of the pixel to red (Red=255, Green=0, Blue=0).
   
   Alternatively, you can just copy the config.bmp file attached here to replace the original config.bmp.
   
   This step changes EditTheSims2 to a region with one small city.
   .
3. Copy the terrain .SC4 file from The Sims 2 into the SimCity 4 Downloads directory:
   ...\My Documents\SimCity 4\Regions\Downloads
   
   Note: The city name displayed in-game may not match the name of your SC4 file. I usually try to keep my Downloads directory empty, so that it's easy to find the SC4 file that I want.
   .
4. Run SimCity 4 again to import your SC4 file and edit the terrain:
   - Make sure that you are looking at the EditTheSims2 region.
   - Click on the city to bring up Start New City. The EditTheSims2 region will have only one small city in it.
   - Click on the Import icon to bring up the Small City Import dialog.
   - Select your city from the Downloads folder and click Import City. If you cleared out your Downloads directory first, then it will contain only 1 small city, so your SC4 file will be easy to find.
   - Click on the city again to bring up the city information, then click the right arrow to edit the city.
   - You'll notice that the city is mirror-reversed from your TS2 neighborhood - this is expected behavior. Change the city as desired, then save and exit from SimCity 4.
   
   Note: The first time that I did this, I didn't have SimCity 4 Rush Hour / Deluxe installed. Turns out that Strangetown was created with Rush Hour, so it wouldn't import. Depending upon how your city was created, you may need the SimCity 4 Rush Hour expansion pack or the SimCity 4 Deluxe edition.
   .
5. Copy your SC4 file from the SimCity 4 region:
   ...\My Documents\SimCity 4\Regions\EditTheSims2
   back into your TS2 directory:
   ...\My Documents\EA Games\The Sims 2\SC4Terrains
   .
   You may want to rename your SC4 file, rather than replacing the original one - just in case you aren't happy with your changes.

Replacing the neighborhood terrain:

1. Create a temporary neighborhood in the Sims 2 using the edited SC4 file.
   .
2. Run HoodReplace. Select the temporary neighborhood in the left (from) listbox and the old neighborhood in the right (to) listbox, select which elements you wish to copy: terrain, roads, bridges, etc, then click on the Copy button.
   .
3. Delete the temporary neighborhood created above.

Cleaning Up:
If your new terrain is different than your old terrain, you may notice some issues such as lots, trees and decorations which are above or below the level of the terrain. You can often fix these issues by picking up the object and then placing it back into the neighborhood.