I have just released CSS Overwrite Plugin. This is the first plugin I created for lifetype.
It is in fact an alternative for the TemplateEditor plugin. This allows blogger to overwrite an existing CSS in a template or create/import CSS in a completely blank template.
To use it. Just paste de code below in the header.template of the template that should be overwritten. You can put it just after </head>
{if $cssoverwrite->isEnabled()} {/if}
you can download it here