What you are looking for is packForget and it's associate methods. You can pack a window with widgets, packforget all or some of the widgets so they are removed from the screen, reconfigure the widgets, then repack them. A simple example:

#!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $top = new MainWindow;

my @counts = ('a'..'z');
my %cbuttons;

my $frame = $top->Frame()->pack();

setup_page();


$top->Button(-text => "packForget",
          -command => sub{
               my @w = $frame->packSlaves;
              foreach (@w) { $_->packForget; }
         })->pack();


$top->Button(-text => "repack",
          -command => sub{ &setup_page  })->pack();

$top->Button(-text => "Exit",
         -command => sub {exit})->pack;

MainLoop;
             

sub setup_page{
for (1..4){

 my $text = shift @counts;
  $cbuttons{$_}{'cb'} = $frame->Checkbutton(
    -text     => $text,
    -variable => \$cbuttons{$_}{'val'},
    -command  => \&SetState,
   )->pack;
  }
}
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