You should alter the "skin/common_files/customer/left_bar.tpl" template.
Or the one for the active skin e.g. "skin/2-columns/customer/left_bar.tpl" if any.
This code is used to show categories:
Code:
{include file="customer/categories.tpl"}
This one for manufacturers:
Code:
{if $active_modules.Manufacturers ne "" and $config.Manufacturers.manufacturers_menu eq "Y"}
{include file="modules/Manufacturers/menu_manufacturers.tpl"}
{/if}
So, you need to move the code fragments as required.
Check our Help portal for more info ->
http://help.qtmsoft.com/index.php?title=X-Cart:Editing_Skin_Files