What hydraulic fluid should I use for a John Deere 410J TC, and do I need to fully drain the system if I'm not sure what oil is already in it?

[Ryxilo Trader]

I have been looking for some advice on my John Deere 410J TC. I recently blew a hydraulic hose (not a big deal), but now I'm stuck figuring out the correct hydraulic fluid. I stopped by a Deere dealer, and even though they weren't 100% sure, they gave me a few different options. The manual also says not to mix oils, which has me a bit concerned.