Forumlar / Cotonti / Support / Cotonti Logo??

hello, i have a question. how do i change the logo that says COTONTI on the header of ALL the skins?
Please comment and help im new to cotonti and literally just made my site

By the way, for the recently NEW release of cotonti, people get this error message that says:

Fatal error: Uncaught exception 'Exception' with message 'Your "./datas/cache/templates/" is not writable' in /home/a3604698/public_html/system/xtemplate.php:184 Stack trace: #0 /home/a3604698/public_html/system/xtemplate.php(39): XTemplate->restart('skins/sed-light...') #1 /home/a3604698/public_html/system/header.php(92): XTemplate->__construct('skins/sed-light...') #2 /home/a3604698/public_html/system/core/index/index.inc.php(34): require_once('/home/a3604698/...') #3 /home/a3604698/public_html/index.php(20): require_once('/home/a3604698/...') #4 {main} thrown in /home/a3604698/public_html/system/xtemplate.php on line 184

all they have to do is set the cache folder to CHMOD: 777