You dont even need to install anything, it can simply be done via SOC.
You simply create a Zip file, then rename the extension as pk3, and then You open it with slade.
Now you create a folder called "Skins".
Inside that folder you create a text file called "P_Skin"
And then you type inside the following:
"
name = sonic
flags = SF_MULTIABILITY
"
And voila! there you have a spammable thok Sonic.