Plugin Install error

my wp-content and public_html folders are set to ch755, because my host (seo-host) does not allow a 777 on the server

I uploaded the plugin and clicked install
and I get the following error

"Installing Plugin from file: 812572466_sitemaps-all-in-one-seo-5.zip

Unpacking the plugin package

Folder already exists.: install.txt

Installation Failed"

I tried installing several plugins, but I get the same error.

what could be the problem? can someone help

thanks in advance

Sean

BTW. I read install.txt

and realized, its not a one click install, like in WP

followed all the instuctions,

However, I dont find the plugin in the admin section/installed plugins
I was looking for it to activate.

It looks like I may be missing something.