To modify templates of ehcp or change logos/images, follow these:

go to /var/www/vhosts/ehcp/templates/xp5-z7/en folder...
if you will change other template go to respective folder in templates dir...

Then modify html files there... such as loginpage_en.html, template_en.html..

dont forget to put image links/src refs with respect to ehcp folder, since these html files are displayed with respect to ehcp folder... not templates/default/en
place images/logos in ehcp/images folder...
or alternatively, you may use full path for images such as and put images in templates folders...

have a look at http://www.ehcp.net/?q=node/250 too