Growing Lean

Hey I am a 20 yr male from Oz. I have been training for about 8 months and Im happy with the way I have been growing , but I currently have around 12.8% body fat. I am naturally a failry slim build , but by no means skinny. I want to get to around 9-10% just give me some more definition during the growth stage. Can anyone make any suggestions on what the best way to approach this goal would be? Also has anyone had any experience with tanning pills? I work an office job and I dont find the time to get much sun , has anyone had any success with them?