Talk to The Fixer in the yard, he will ask you to help him get something for Flossy. Follow the quest to cell A-309, and interact with the Teddy (the plush fox toy) there, you will find a note telling you to do the laundry, but to take a shower first.
The laundry is on the first floor of Cell Block A, to the right of the showers, and has a level 1 door lock. If you go to the showers first, look in the janitor cart and you will find another fox toy with a note that says 6014 - this is the door code for the laundry.
Enter the laundry room and interact with the fox toy there to get the altered biocell. Also in the laundry room is the basketball for the Don't Reach, Kid achievement.
You then have two options:
- Use the altered biocell yourself at any time (while it is in your inventory) to gain 5 praxis points and unlock your augmentations and get the achievement.
- Talk to Flossy and promise to give the biocell to his friend Red Shoes in B-Block in exchange for a key card (you can also get this key card by telling Flossy that you refused the pills). The player must navigate to B-Block and speak to Red Shoes in order to give him the altered biocell. Doing so awards the achievement.