When breaking in a motor, heat cycles are what is important, not time or distance. It's important to heat the motor up using different speeds and RPMs and also using all the functions such as 4-wheel drive, the locker and high and low gear. Then let it completely cool down. Once you do this half a dozen times, you should ride it like you will normally be riding it.
Another thing that I think is very important is to change your oil after the first hour or two of riding, and then again after about 10 hours. Most of the filings and junk that is going to come lose is going to happen right away on a new motor. You want to get it out of there as soon as possible. I also replace the drain plug with a magnetic one right away
I don't remember exactly what the manual said, but I do remember not agreeing with it. It seems that they want you to baby it for a certain amount of time. I don't agree with this. Besides, unless you actually watched them take it out of the crate and you were the first one to ride it, you have no idea how it was run before you bought it.