The Fix

SM08: The Fix is a side mission that can be completed during Adam Jensen's second visit to Prague. If you retrieved the neuroplasticity calibrator and finished either M11: Confronting the Bomb-Maker or M12: The Heist, Václav Koller will contact Jensen, saying he is ready to operate on him.

Obtaining a Calibrator
The neuroplasticity calibrator can be obtained by completing SM04: The Calibrator. Alternatively, if SM04 was not completed, another calibrator can be obtained from the Tai Yong Medical Vault in the Palisade Property Bank.

Once a calibrator has been obtained and either M11: Confronting the Bomb-Maker or M12: The Heist has been completed, SM08 will trigger.

Go See Koller
This side mission has only one objective and is very straightforward. Simply make your way to Koller's workshop and tell him to operate on you and he will install the calibrator, allowing you to use all of Jensen's augments without having to deactivate others.