Thank you Christopher for giving the reply I wanted to give. Didn't really know how to word it, but you already did it :-)

As Christopher says, learn loads of Slash songs/licks. Then you will discover in what kind of way he plays, it's rather difficult putting it up here in text.

Perhaps you can request a Slash Artist study here at GT, that should be awesome and I think LOADS of people will like that :-). Currently there are only three lessons I'm aware off in the style of Slash:

http://www.guitartricks.com/lesson.php?input=13649

http://www.guitartricks.com/lesson.php?input=13694

http://www.guitartricks.com/lesson.php?input=12689

Give these a try.

JJ