Step 1: Press Command+Spacebar.
Step 2: Type sys, and then press Return.
Step 3: Type a, and then press the Down arrow key to open the Accessibility window, where you can set preferences.
Step 4: Select Keyboard > Keyboard Preferences.
Step 5: Select the Shortcuts tab.
Step 6: In the Shortcuts category table, select Mission Control.
Step 7: Find the assigned shortcut that you want to replace.
Step 8: To close the dialog, press Command+W.