I recommend to use the iFixit Opening Picks for this step! Otherwise you could scratch/damage the keyboard or frame by metal on metal!

Place it between the keyboard and the frame. I started near the on/off button to make a opening.

Just go around the whole keyboard with the opening picks, slide it through every side of the keyboard, except for the under side (there are no clips there).

Just free all the clips, you should hear some pops. Do not pull the keyboard out, just free it from the clips which are holding the keyboard. The clips that are holding the keyboard are pretty strong, so you need a little force to free it.