There isn't really an offical way to make these, but I made this way and decided to share it, as I saw someone saying there needed to be an easier way to make them.
Depending on what style your fangame is, you'll need to download one (or both) of these files to get the characters.
(Warning: Plot spoilers in both images.)
In our example, let's make an intro (the audience mutters before the judge slams the gavel) using Phoenix, Maya, the Judge, and Payne. Let's also use Phoenix Wright style court.
The way I do this is taking the minis and making them into their own foregrounds, and then stacking them.
To make the images, I'll use Paint.NET (free download) and then put the main court in layer. Then cut out the minis and place them in their respective locations, then deleting the court layer and making it PyWright transparent. Here's an image tutorial:
Download to see for yourself, and feel free to copy what's there and add more to use in your fangame.
Video of the script being played out: