How to Install and apply Mods on dungeon siege 2 on steam

i am trying to install the pappagamer mods on my steam version of dungeon siege 2, mainly for the six slot mod but i have no clue at all how to do it i am not to inclined when it comes to mod talk or even computer talk, i literally have no idea what i am doing if anyone can take some time to dumb it down and walk me thru it i would much appreciate it please and thank you
and if anyone knows how i can get the expansion plz let me know

this is the link to the page i got the mods from
http://www.papagamer.com/index.php/blog/60-dungeon-siege-ii-extras