Here's some test code I threw together. If you want to preserve the other slots, you'll likely have to use Symbol's gensym to make a new typeglob and assign all of the other slots to it, then use it to replace the old symbol. If you're comfortable with the following code, there you go:

#!/usr/bin/perl -w

use strict;

package destination;

package main;

use Test::More 'no_plan';

{
    no strict 'refs';
    *{'destination::foo'} = sub { 'foo' };
}

is( destination::foo(), 'foo',   'install a sub' );

{
    no strict 'refs';
    my $d = *{ 'main::destination::' };
    delete $d->{foo};
}

ok( ! destination->can( 'foo' ), '... now remove it' );
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