Downloaded blogger template with psd files how to edit

I've no idea how to use photoshop,doesn't matter which version so I got myself photoshopcs6 extended. So i downloaded some premium blogger templates and then I wanted to change the logos, the thing is it came with psd files and xml files here they're http://imageshack.com/a/img29/3037/p72l.png and http://imageshack.com/a/img23/5662/m8pk.png How woul'd I add my own logo by editing those psd files, Also I want to tile a backgroung image on blogger this is the site http://callofdutyghostspcedition.blogspot.com/ with the background image.