This cheevo will be awarded for completing all story missions in "Episode V: The Empire strikes back"
This is story related and therefore unmissable.
The story missions are;
1. Hoth and cold
2. Assault on Echo base
3. Never tell me the odds
4. Hibernation station
No need for a detailed walk-through of each level as its fairly simple and linear, plus there are plenty of marker points to the next objective.