(motorcycle) How do I remove this bolt???

I have a 1981 Yamaha seca 750 I purchased off of marketplace a while ago and Im having trouble replacing the oil filter because of this one bolt. This is my first project vehicle so I’m still learning a lot about even the most basic things

I’ve doused this bolt in wd40 for weeks and had over 5 buddies of mine come with all sorts of tools but we just cannot get this off. Any advice on what to do would be greatly appreciated!

Here’s a video of what the bolt currently looks like. I can send more pics if anyone is interested or needs more details!