Unfortunately there is no easier way other than start doing it and learn from mistakes.
Use Discord for more real-time answers and help since there are plenty of skilled users on-line there.
As mentioned earlier, help on usermods can be obtained from usermod authors or other users that have successfully implemented them.
I have posted the setup needed for PlatformIO + Visual Studio Code to compile 5 usermods that I modified or created. There is no other thing needed to be done other than create platformio.ini (or platformio_override.ini) entry as shown above. After this is done just click Build (or Upload) menu item in PlatformIO tab.
I am not going to describe how to do things in PIO or VSC since there are plenty of resources on-line, some in linked videos above.
I have being playing with this stuff for the first time today on a try to make my TTGO-T-Display to work with the already built usermod and I just found a way to force the Visual Studio to compile using the usermod.cpp for that specific project.
The instructions of the Readme.md must be followed, however there is a missing part which is that you shall replace the usermod.cpp from the folder wled00 for the usermod.cpp on the usermod library. That’s the trick to make a usermod to work when declaring it as a #defines doesn’t work.
If you know how to install software and if you know how to compile I bet you can figure out how to change compile parameters. If I was able to comprehend how to write a usermod (or modify one) within a couple of months just by studying supplied ones, you can too. Let alone just use one!
v2 usermods require change in usermods_list.cpp where you #include appropriate usermod .h file (preferably by using/copying provided existing usermods) and creating a usermod .h file itself.
Usermod .h file may contain any or all of the virtual methods defined in fcn_declare.h in usermods section.
What they do is up to you.
There is also an empty usermod_v2_empty.h (with a minimum layout and instructions how to write a usermod) provided, as well as complete example usermod_v2_example.h with readme.md.