From the PRO CLUBS MENU simply click on your character in the MY PRO tab (the biggest tile that says your name and level on it. Then choose any PLAY STYLE, click ATTRIBUTES and unlock all of the traits within a skill-tree. I chose the left-most skill-tree in the PHYSICAL section and it requires 29 Skill Points. Please note you must completely unlock the tree, that includes a 1/2 skill, you must have all of them, for example it should state 2/2.
I created this video to help:
I hope this helps.