Have at least four available skill points and a skill ready to be
evolved to its fourth form. While evolving a skill from level 3 to level
4 at the squad menu, press A + X to regain all spent squad points and
keep the skill evolution. This works best if you level a skill from 0 to
4 (10 points) at the same time. Repeat this process to fill every line
of your and your crew's skill tree. Note: You cannot do this trick in
the patched version of the game. You can delete all patches for the game
by using the "Clear hard drive cache" code for the Xbox 360