Instructions
Download and install the latest version of Lunar Magic if you have not yet done so.
Download the "Super Mario World" SNES ROM from a site such as CoolROM or ROMhustler and place it in the same folder as the Lunar Magic program.
Start Lunar Magic and click "File," then "Open Rom." Click on "Super Mario World" and then click "Open."
Click "Editors" on the file menu and select "Overworld Editor Window." This will bring up a new screen that displays the game̵7;s overworld map.
Click the "Layer 1 16x16 editor mode" button at the top of the new screen. You'll see a purple square underneath your mouse cursor.
Click "Editors" and then "16x16 Overworld tile selector." A new window will display all the available overworld objects.
Click on the "Warp Pipe" in the new window and right click where you want to place the pipe anywhere on the overworld map. Right click another spot on the overworld map to place your second warp pipe (the destination).
Left click the first warp pipe you created to highlight it. Click "Overworld" and then "Star and Pipe Tile Settings." Select one of the settings labeled "Overworld Map" from the drop-down menu next to "Exit Index to Use." If you are creating a new custom map, it doesn't matter which setting you pick, but if you are modifying the original map, it will overwrite the previous warp pipe that had the setting.
Select "No Setting" next to "Destination Exit Index" and click "OK." If your warp pipe leads to a level and not to a second warp pipe, select one of the locations listed just below the "No Setting" option.
Left click the second warp pipe you created. Select the "Star and Pipe Tiles Settings" again and choose a different "Overworld Map" setting than you did for the first pipe. Next to "Destination Exit Index," select the setting you used for the first pipe's "Exit Index." This means the second pipe now links to the first.
Left click the first pipe again and open the "Star and Pipe Tiles Setting" menu. Select the "No Setting" next to "Destination Exit Index" with the setting you used for the second pipe̵7;s "Exit Index." Your first pipe is now linked to the second.
Click "File" and then "Save Overworld to Rom" to store your changes. Exit Lunar Magic and open a SNES emulator such as ZSNES.
Load the ROM and play to make sure that your overworld warp pipes are working.