I know that your not supposed to cut cross grain when it comes to planing the wood. But when I am in such a spot what is a good way to do this? The easiest would be to take shallow cuts, as told in a previous question. But what are thing that can be done to be on the safe side. Just to prevent the chip out and all would be nice. Edit: This is done with a 13" thickness planer.
For parts too wide for your planer, there are a couple different options. If you have a router, you can make a router sled, and use the router to surface the wood. I believe you will find this process spelled out in other posts on here if you do a quick search.
Depending on how much material you need to take off, you could run it through a drum sander, or do the hand tool route and you a hand plane.