There are 4 scenarios in the El Dorado campaign:
1. Tales of La Canela
2. The Split
3. The Amazones
4. The Cannibals
Win every scenario of the campaign using the cheat code “i r winner”. Then, to trigger the achievement, win any scenario of any campaign without using cheat codes. The quickest scenario is the 1st scenario of the William Wallace Learning Campaign: Marching and Fighting.