Update / Add Navigation Properties with Entity framework -

i using repository , unit of work pattern entity framework 6.

my entities (model classes) have following relationship:

                            article       ______________ __________|__________ _______________     |              |                     |               |    tags         images     references   authors        reviewers 

whenever article created, data inserted tables (i.e. article, tags, images, references, authors , reviewers. there one-to-many relationship between article , other child tables. add method passed article object following:

public class article  {    public int articleid {get;set;}    icollection tags {get;set;}    icollection images {get;set;}    icollection authors {get;set;}    icollection reviewers {get;set;} } 

adding database simple , doing following:

public void add (article arc) {   this.context.article.add(arc);  } 

for update, not getting best way of doing this. user can pass on object of article amended navigation properties and/or added more. e.g. existing reviewer can amended added more.

i have composite key in each of navigation properties (e.g. tags tagid , articleid).

please suggest approach