To unlock this achievement you must attain at least 80 reputation in the following towns and villages:
The Mill, Rovna, Pribyslavitz and Vranik are not counted among those relevant to the achievement. If you completed the prologue without getting Henry into too much trouble, Skalitz should be fine. For the others, it helps to have the 'Infamous' perk active. Completing quests in each town and village will gradually gain you reputation, assuming you complete the quests in an honourable way. Tipping merchants will also improve your reputation incrementally.
Merhojed can be a tricky one, particularly if you fail to aid the residents in their plight of disease during the main quest. The easiest way to increase reputation is by repeatedly haggling with merchants and providing them with more Groschen, whether by purchasing or selling. A large boon to reputation in Merhojed can also be acquired by fast travelling between Samopesh and the Inn in the Glade until you encounter bandits on the road. Help the guards to kill the bandits and your reputation will increase.
For the Monastery, complete as many side quests as possible while you are stuck there during the main quest 'A Needle in a Haystack'.
Note: While you are working toward increasing reputation for each town or village, avoid any criminal activity such as stealing or needless killing.