Step 1: Eliminate the consonants that appear after the letter 'M' in the English alphabet.
I. MAGNIFICENT
II. INGRATITUDE
After eliminating we get  - 
I. MAGIFICE
II. IGAIDE
Step 2: Eliminate the letter that is followed by vowel and preceded by a consonant in the English alphabet.
I. MAGIFICE
II. IGAIDE
After eliminating we get  - 
I. MAGIFICE
II. IGIDE
Step 3: Eliminate the letter third to the right of 'G'.
I. MAGIFICE
II. IGIDE
After eliminating we get  - 
I. MAGIFCE
II. IGID
Step 4: Eliminate the letter which is 2nd to the left of the letter which is 2rd from the right end.
I. MAGIFCE
II. IGID
After eliminating we get  - 
I. MAGFCE
II. GID
Step 5: Eliminate the vowel which is immediately preceded by a consonant in the English alphabet.
I. MAGFCE
II. GID
After eliminating we get  - 
I. MGFC
II. GD
Step 5 is the last step.
Six letters in total are left.