how to install addon tool in zencart?

sorry, I am new here,

I don't know how to install tool in the zencart?
such as simple seo tool?

can you tell me step by step to install a tool ?

thanks

There are no 'tools' in Zencart. The program you mentioned is known as a 'mod' and usually contains installation instructions.

Many here believe that SEO URL mods are no longer necessary.

Just to expand a little on the previous reply. Any mod with come with a readme file that explains how to install it. Some are easier than others. Be sure to read through all the steps before you begin.