Trying to upgrade

I am trying to upgrade to 3.0.3. I keep getting this error and I am not as savvy and am having a difficult time trying to resolve this issue. Can anyone assist me in explaining what I am doing wrong. Thanks in advance, Kevin

Warning: copy(/home/content/k/w/i/kwilcox35/html/wp-admin/includes/update-core.php) [function.copy]: failed to open stream: Permission denied in /home/content/k/w/i/kwilcox35/html/wp-admin/includes/class-wp-filesystem-direct.php on line 131
Could not copy files.

Installation Failed