I would not touch any of the lines.
Brown stays at 1RW and Williams stays at 3RW. The Kings need balanced scoring and Williams to put it in basketball terms can "create his own shot", Brown thrives playing with better players like Kopitar and provides a physical presence that line wouldn't have with Williams. And if the third line was King/Stoll/Brown I think it struggles to put up points.
That 70's Line breaking up makes absolutely zero sense on so many levels. Carter plays much better at C and despite all the optimism Mike Richards has a lot to show on both sides of the ice before he is returned to a scoring line role, I think people quickly forget how ineffective the Carter/Richards lead second line was last season, not only offensively but especially defensively where they were clearly the Kings biggest defensive liability. This also forces Tyler Toffoli down to the bottom six, something that doesn't put him in a position to succeed.
You could possibly switch Richards and Stoll, especially if the long term plan is to keep Richards and lose Stoll after the season. Stoll will provide better defense and faceoffs but Richards adds more of a scoring and skill element to this line with King and Williams. This could possibly be a training camp battle/decision between two veterans.