Soo I bought a single conversion kit from MIB miami electric boards and it came with a 12S2P battery a vesc and an uncensored 250 KV motor. I’ve read that with a 12S battery Its better with a motor with a bit lower KV, like maby 170 - 200. Can I just buy a new censored 170 KV motor and replace it without changing the VESC settings? Or is it more to it?
Sorry for any bad spelling, English is not my first language…
250kv is wayy high to run at 12S. I run a 190kv at 12S and that is slightly dangerous. Buying a new 170kv sensored is a much better option. And as with any motor, you will need to at least do a motor detection and tuning of the settings for that specific motor. There are some videos and many threads on the forum describing what settings people have used. I am sure you would be able to find one for 170kv by using the search function. 
As @ShutterShock said 250kv is too high for a 12s pack, but you can still use it by unticking the negative torque option and limiting the ERPM to 60k in the BLDC tool. I would use a 190kv 6374 motor, both @torqueboards and @JLabs have them/will have them soon.
Yeah you could do that, I think would probably just get a different motor cuz I’ve already blown a drv lol