How can I make my custom heads wearable?

[uSkizzik]

So, long story short, I've been trying to add custom heads to the game and I've been having troubles for the past week.
I figured out the tile entity and then the item but now I'm having issues with wearing the custom head.
Minecraft seems to be hard-coded to render heads from the vanilla skull renderer. This means that I need a way to change the vanilla player renderer to render my heads from my custom skull renderer... But how?!
I've read old forum topics and I found out that I need to use the RenderPlayerEvent.Pre event and that's all I know, nothing more.
Any ideas?

[uSkizzik]

Wow, thank you so so so much! It finally works!
I already had most of the stuff but my issue was that I was using a custom renderer instead of modifying the vanilla one.