Start the intro/main riff of this song on the 9th fret of the first string. Play 2 eighth notes, then pull off to the 7th fret in sixteenth note rhythm; quickly play the 9th fret of the second string. This is a recurring pattern. Refer to a recording of the Trooper for what it sounds like.
Repeat the recurring pattern, starting on the 7th fret of the first string. This means you will be pulling off to the 5th fret, then playing the 7th fret of the second string.
Continuing in the same rhythm as the first two repetitions of the pattern, start on the 5th fret of the first string, pull off to the 4th fret, and then play the 5th fret of the second string.
Start the turnaround on the 5th fret of the third string, 5th fret second string, 5th fret third, then the 7th fret of the third string, all in eighth notes. Hang on that last note for just a moment, then start the whole thing over again. Play up to this point four times.
Begin the second half of the intro by playing the verse riff, which is Steve Harris' signature gallop rhythm (eighth-sixteenth-sixteenth). Play two measures of E (7th fret, third string), two more measures the same way, then a two measures of C (3rd fret, third string), turnaround, and two more measures of E followed by the now familiar turnaround. Repeat this Step twice to finish out the intro.
Remain tacit (silent) for the first half of the first verse, only chiming in with the turnaround riff as appropriate (again, refer to the recording for the specific timing with the vocals)
Continue the second half of the first verse the same way you played the second half of the introduction, starting at E, moving to C and back to E, with the turnaround thrown in every other measure.
Play all the other verses using this pattern, except you don't remain tacit for the second and third verse at all.
Play E (7th fret, third string) in that gallop rhythm for two measures, except this time around, don't do the turnaround at the end of the second measure. Instead, move down to D (on the 5th fret) just before the downbeat of the next measure. This is called an anticipated harmonic change.
Play the D for two measures, finishing the last of the two measures by playing E on the 7th fret on the last half of the last beat.
Play two measures of E, but this time, use the open E string, continuing in the same gallop rhythmic pattern. Again, anticipate the shift to D.
Play D for two more measures, anticipate the shift, and play E on the 7th fret for two more measures, culminating in a return of the turnaround riff to take the song into the interlude, which is the same as the second half of the introduction.
Play the first solo's rhythmic backup with the gallop rhythm, one measure each of the following notes: E, D and B.
Arpeggiate a C power chord in eighth note rhythm (play the notes individually in order: 3rd fret, third sting, 5th fret, second string, 5th fret, first string). Repeat with the D power chord, two frets higher. Repeat those four measures four times.
Continue with the gallop rhythm, but for the second solo, play the following notes: A, G, and E on the 17th, 15th and 12th frets respectively.
The last measure is two beats of F followed by two beats of G. Repeat those four measures four times.
End the song by playing the interlude again, this time ending abruptly on the last note of the fourth repetition of the riff.