Instructions
Download and unpack the stage.
Open your ̶0;Mugen̶1; folder. Your "M.U.G.E.N." installation is located where you first unpacked it. Double-click the ̶0;Stages̶1; folder.
Copy the downloaded stage .def file to the ̶0;Stages̶1; folder. If there are any .sff files included in the stage download, copy those over as well.
Select the .def file, press ̶0;F2̶1; to highlight the filename, and then press ̶0;CTRL̶1; and ̶0;C̶1; to copy the .def file.
Return to the main ̶0;Mugen̶1; folder and then double-click the ̶0;Data̶1; folder.
Right-click on ̶0;select.def.̶1; Select ̶0;Open With,̶1; and then click ̶0;Notepad̶1; from the contextual menu.
Scroll down to the ̶0;[Characters]̶1; section. If you wish to link the new stage to a specific character, add ̶0;stages/stage.def̶1; to the character line, replacing ̶0;stage.def̶1; with the filename copied into your clipboard.
For example, to change Kung-Fu Man̵7;s default stage to stage.def, his character line will be ̶0;kfm, stages/stage.def̶1;.
Scroll down to the ̶0;[ExtraStages]̶1; section. Add ̶0;stages/stage.def̶1; to a new line in this section, replacing ̶0;stage.def̶1; with the stage filename. These stages will be available as selections in both "VS" and "Watch" modes.