How Do U Add These Things On On This Site?

this site has some cooool stuff. but i want to know how to add these things in your map.. i think i know how to add the skins.. but i want to add the custom weapons and stuff.. this looks cool heres the site:
http://www.campaigncreations.org/wa...ies/index.shtml

it says to use the special effects trigger? where is that and how do i use it?

They're probably referring to the "Special Effect - Create Special Effect on Unit" Action. Try using it to attach the imported attachment to a unit's left hand/right hand/whatever.