Complete Challenges

• 1). Load up Halo Reach on your Xbox 360. Select "Matchmaking." This will take you to the lobby.
  
  
• 2). Press "Start" on the controller and select "Challenges" from the menu.
  
  
• 3). Look through the four daily challenges and the one weekly challenge to see what they all are and which provide the highest amount of credits.
  
  
• 4). Select "Team Slayer" and "Start Matchmaking." Wait to be connected to other players and for the game to start automatically.
  
  
• 5). Carry out the tasks in the game that will complete both the daily and weekly challenges. This will give you a large amount of extra credits and allow you to level up quicker. Repeat the process every day.
  
  

Get Assists

• 1). Load up Halo Reach on your console.
  
  
• 2). Select Matchmaking and then select any match making game you like such as "Team Slayer" and "Big Team Battle."
  
  
• 3). Click on "Start Matchmaking" and wait for the game to start.
  
  
• 4). Follow the other players on your team around the map and attack opposition players. Even if it is your teammate who gets the kill, you will still receive a number of credits for an assist.
  
  

Firefight

• 1). Select "Matchmaking" from the menu and select "Firefight."
  
  
• 2). Select "Gruntpocalypse" as the Firefight gametype you would like to play.
  
  
• 3). Select "Start Matchmaking" to search for a game.
  
  
• 4). Kill as many grunts as you can within the time limit. Grunts are much easier to kill than any other enemy. The large number of grunts to kill will allow you to amass numerous credits to increase your level fast.
  
  

Complete the Campaign

• 1). Load up the Halo Reach game on your console.
  
  
• 2). Select "Campaign" from the main menu.
  
  
• 3). Select "Difficulty" and choose "Heroic." Although playing on "Legendary" difficulty will result in you gaining more credits, it is a much harder difficulty that will take you a substantially longer time to complete.
  
  
• 4). Select "Start Campaign" to begin campaign mode.
  
  
• 5). Work your way through the different levels until you complete the campaign. At the end of the campaign you will receive credits for headshots, kills and missions completed. These credits will help increase your level.