Here's another option:

use Modern::Perl;
use Data::Dumper;

my @array = qw/1 A 2 B 3 C 4 D 5 E/;
my $i = 0;

say 'Before:';
say Dumper \@array;

@array = grep !($i++ % 2), @array;

say 'After:';
say Dumper \@array;
[download]

Outout:

Before:
$VAR1 = [
          '1',
          'A',
          '2',
          'B',
          '3',
          'C',
          '4',
          'D',
          '5',
          'E'
        ];

After:
$VAR1 = [
          '1',
          '2',
          '3',
          '4',
          '5'
        ];
[download]

This uses the modulo operator within grep to let only the even-numbered elements of the array pass.

Hope this helps!