If it is a mono (not stereo) mic then not possible.
You could try making a pseudo stereo version of your mono recording …
make a dual mono and apply different equalization to each track, (say bassy on one side trebley on the other), then make a stereo pair.
<<<How would I go about to remixing a recording done using one microphone? As in moving certain parts to the center, making the drums louder, etc.>>>
I read that as wanting to take a mixed, produced stereo song apart into individual instruments and remix it.
The best you can do is separate the main singer from the rest of the band with the Vocal Removal and Isolation tools. If the singer is in the middle of the stereo show and the drums are too, then the drums will go along with the singer.
In practice, this rarely works because compression (MP3, AAC) fights you and any stereo special effects applied to the voice messed up the tools. If it’s a mono show, there are zero tools.
So the short answer is no unless you have access to the original studio recordings.
Koz
You start with the multi-track recordings - each instrument and voice on its own track. Then you mix them.
“Remastering” is different from “remixing”.
In order to remix (as per your first post) you need access to the original multi-track recording. Only then can you make the drums louder, or move instruments around in the stereo field. Once the song is mixed, all those options are gone.
Remastering is a totally different animal. Even then - to do it right - you’d want access to the original, pre-mastering stereo mix.
In your case it seems like you’re saying you have a recording done with a stereo microphone. So it probably hasn’t been “mastered” yet. You have the original recording, so to speak.
There are a few tools you can use to make it sound “better” - whatever your definition of “better” is. You can compress the living daylights out of it so it screams at you like a TV commercial. Or you could apply gentle multi-band compression to bring out the nuances, emphasize the drums and bass, highlight the vocals, etc. You can pump up the low frequencies so it makes the windows in your car rattle. It all depends on what your goal is, who you think your audience is, and the genre of the music.
Your basic tools are compression and equalization. Use them gently unless you are looking for an extreme effect. Work on a copy, because in Audacity once you close the project your changes are written in stone.
For compression, “everyone” agrees that this is the plugin you want to download and install in your plugins folder: http://pdf23ds.net/software/dynamic-compressor/
It shows up in the Effect menu as “Compress Dynamics”. Play with it to learn what it does.
For equalization (tone control - boost the lows, tame the highs, etc.), Audacity’s built-in Equalizer effect is fine.
Other tools you might want to consider are: Audacity’s built-in Compressor effect (which tames the peaks); and a reverb if your recording is too “dry”.
Google “music mastering” and you’ll find articles to get you started.
I hope this is what you were looking for.
– Bill