2009 asw 7150 carbide crankcase
 

So i bought a used carbide off of someone on craigslist for about $600. I put new tires on it, new brake pads, new master cylinder, unifilter, bigger jets in the carb and gave it a tune up. Of course the last thing I checked was the gear oil for the crankcase. I pulled the drain plug, nothing came out. So i decided to fill it with oil, when I realized it was pouring out of the bottom of the crankcase... Apparently the previous owner backed into something cracking the left crankcase cover.

My question is, what's my best course of action here? The crack looks too long for jb weld. Plus I would rather do it right and have a more permanent solution. I priced a left crankcase cover over at the manufacterers website and they want $180 for it. Can anyone tell me how big of a job this cover is to replace? Does the entire engine need to be torn apart? If it does what other parts/seals should I look into replacing while I'm doing this Job. Also are there any special tools you can think of that might make this job easier for me (I already have sockets, impact wrench, etc...). I'm really lost here and just want to get this thing up and running.

Thanks for taking the time to read this, here's some pictures of the damage:

https://i.imgur.com/1697cHT.jpg

https://i.imgur.com/JxMSHN8.jpg

https://i.imgur.com/gzm8VKW.jpg