From my experience with modbase, it's not terrible. You'll need to add one tag to your existing files:
[OBJECT:<object type>]
So a file with bodyparts would be [OBJECT:BODY], entities are [OBJECT:ENTITY], etc.
You'd then have to make a folder that contains all your files (which would be placed in the modbase folder), and a text file (named dfmod_<nameofmod>) which contains the information modbase uses to find and add your mod, which includes a NAME tag, description, etc, along with the most important parts, the DIRECTORY tag (named the same as the folder with all your files in it) and the [MSECT] tag, followed by a series of FILE tags named after your txts.
(example, with notes # showing what each does)
For a mod named "example" in an "example" folder with "creature_example_file" and "entity_example_file"
dfmod_example
[OBJECT:MOD]
[MOD:EXAMPLE]
[NAME:example mod]
[DIRECTORY:example] #The folder in the modbase folder that contains your files. So probably something like civforge if you name the folder containing your raws civforge.
[REQUIRES:Original DF] #Original DF is a folder modbase automatically makes using the raws already in place when you first run it, essentially serving as a backup of your original installation. You can also make mods dependant on other mods, allowing you to make optional addons.
[VERSION:1.6] #version number, dunno if it's absolutely necessary but it displays in the description
[DESCRIPTION:This is an example mod] #description text. This can be formatted completely normally, EXCEPT use ; instead of : or else it goes all funny. The description will automatically replace ; from the text with :. It'll display a description of your mod.
[MSECT:Example_mod] #This will create a checkbox, which enables/disables modbase loading these files.
[FILE:creature_example_file][FILE:entity_example_file] #Individual files. You could also give each its own MSECT if you wish, or even do MSECTS by groups - for example, one MSECT could be all Civ Forge civilization files, one have all the files that control new objects, one that enables/disables a custom tileset, that sort of thing, though you should be careful about dependencies if so.
Using the above example, on the modbase list this would appear as "example mod", have a checkbox labelled "example mod", which when checked would enable and load the files creature_example_file.txt and entity_example_file.txt as part of the modbase installation (assuming those files were in a folder under modbase named example (C:\Dwarf Fortress\modbase\example, for example, if your DF is installed directly to C:\), and show the description text of "This is an example mod". For multiple MSECTs, if you want to compartmentalize your mod, files should follow each MSECT and then have a new MSECT for each group of files, so instead of the above I'd have
[MSECT:example mod creatures][FILE:creature_example_file]
[MSECT:example mod entities][FILE:entity_example_file]