In Web API 2 with OData, how to update a collection of navigation links ?

Hello,

I was working on a project of SPA application with Web API, OData and DataJS.
I have started a fresh new project with the update to Web API2 and the
Javascript of the previous version.

I have problem to understand how the navigation links work.

I understood how to create a link but I don't get how to update a link or update a
collection of links.

Here's my model :

    class Application
    {
        int Id 
        string Name 
        string Comment 
        virtual ICollection<ApplicationDivision> ApplicationDivisions 
    }

    class ApplicationDivision
    {
        int Id 
        int ApplicationId 
        int DivisionId 
    
        virtual Application Application 
        virtual Division Division 
    }

    class Division
    {
        int Id 
        string Name 
        string Comment 
    
        virtual ICollection<ApplicationDivision> ApplicationDivisions
    }

Following some tutorials, I have added this method to handle adding an 

ApplicationDivision to an Application, I understand the POST verb but not how the PUT verb works...

	[AcceptVerbs("POST", "PUT")]
	public async Task<IHttpActionResult> CreateLink([FromODataUri] int key, string navigationProperty, [FromBody] Uri link)
	{
		try
		{
			if (!ModelState.IsValid)
			{
				return BadRequest(ModelState);
			}

			Application parent = await db.Applications.FindAsync(key);
			if (parent == null)
			{
				return NotFound();
			}

			switch (navigationProperty)
			{
				case "ApplicationDivisions":
					int childKey = GetKeyFromLinkUri<int>(link);
					ApplicationDivision child = new ApplicationDivision();
					child.ApplicationId = key;
					child.DivisionId = childKey;

					parent.ApplicationDivisions.Add(child);
					await db.SaveChangesAsync();
					return StatusCode(HttpStatusCode.NoContent);

				default:
					return NotFound();
			}
		}
		catch (Exception ex)
		{
			throw ex;
		}
	}

I have tested this above code in Fiddler with the POST Request:

/odata/Applications(1)/$links/ApplicationDivisions
Content-Type: application/json
{"url":"http://localhost:51067/odata/Divisions(2)"}

So, I can add a Division to an Application but in my UI, I convert the collection of
ApplicationDivisions to a listbox of Divisions and users can do a multiple selection.

I want to update the collection of ApplicationDivisions with the array of now selected Divisions.
How can I do that ? Should I make one loop to delete the links that are
no longer valid and one loop to add new ones ?  Should it be an array of links in the data part of the request ?

Should it be a Patch verb ?? Or is it my approach that is wrong ?

Thanks for any help,
Claude