You can do this as soon as the DLC/Update is installed. You do not need the DLC for this achievement.
Regardless, head to the main game, not the DLC.
- Press
to access the menus.
- Select 'Character'.
- Press
to Change Skin
- Select the first female skin. After an update, it should be the third skin
. Thanks, Markyshizzle. It may still appear in the second slot. Thanks, HolyHalfDead.
Exit the menus and complete an Online Conquest as normal. Look for the Red Fort circle on your map. Obviously, every fort is different and I cannot give you details on beating the exact fort but you shouldn't have any trouble doing so.
If you are struggling, head to the Such Great Heights guides for detailed help.