Ah, of course!

What you're gonna want to do is make a folder in your mods folder named whatever you want your mod to be named (in my case, "Dogma Lasers").
In order to modify a specific sound effect, you need to copy the file path from how it appears when extracted (if you haven't extracted files for modding, here's a tutorial for that: https://moddingofisaac.com/help/abplus/). For example, the standard brimstone sound effects are located under resources/sfx/v2/ so you need to make folders within your mod folder that go resources > sfx > v2.
After that, add your custom .wav file with the same file name you want to modify within the innermost folder. In order to replace "blood laser medium 3" (standard Brimstone), your .wav needs to be named "blood laser medium 3"
Replace all of the wav files you want to modify, and you're good to go!

Also, sorry if the mod got a bit screwy in the mods folder; tried changing the directory name, which definitely messed some stuff up. Pro tip: don't do that.

Thanks, I made the mod now. I only have to buy the game now lol. I share it from my friend's library so steam won't let me upload it :p

Okay I uploaded the mod, thanks again for help :D