This is complicated. This is a backwards right wheel. The brigade is faced about by companies, starting with the 1st company (right company), and does a half wheel to the right, and then faced about again, the 2nd Brigade is facing west. This movement would allow the 2nd Brigade to flank an advancing enemy and its rear protected on ground vacated by the 1st Brigade.
2) Given the First Brigade's deployment in line facing west, perpendicular to the Second Brigade's initial position, what would it's alignment be given Davis's command "to change front forward on its left"?
This is a "half wheel" by companies, starting with the last company (left company), to the left. The 1st Brigade would be facing South (in this case facing the enemies rear).
From "Parade, Inspection and Basic Evolutions of the Infantry Battalion 4th Edition", adopted from U.S. Army Regs. 1861 and Hardees Infantry tactics.