there are some stages of red alarm i like more than others, i use it for the stage select.
you need to patch the ips file to the rom. if you are on windows then i would recommend LunarIPS. its straight forward and simple to use. this will permanently alter your rom, so be sure to keep a backup.
I’ve seen “patches” here; looked for instructions how to apply them — are they executable files? Sorry to be so “novice”…
If you are in the “Downloads” section of a game and see the possible patches for the game on this site, you should see a section on the right side of the same screen that says: “How to use? Click here for instructions” Click on that and you should see all of the necessary instructions to get an IPS patch applied to a ROM.