Send extra info on register - asp.net-mvc

Question

I am using the default ASP.NET Identity register View, but I also want to pass along the first and last name of a person, how can I pass those variables together with the model that is sent to the controller?
#model Test1.Models.RegisterViewModel
<h2>#ViewBag.Title.</h2>
#using (Html.BeginForm("Register", "Account", FormMethod.Post, new { #class = "form-horizontal", role = "form" }))
{
#Html.AntiForgeryToken()
<h4>Create a new account.</h4>
<hr />
#Html.ValidationSummary("", new { #class = "text-danger" })
<div class="form-group">
#Html.LabelFor(m => m.Email, new { #class = "col-md-2 control-label" })
<div class="col-md-10">
#Html.TextBoxFor(m => m.Email, new { #class = "form-control" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(m => m.Password, new { #class = "col-md-2 control-label" })
<div class="col-md-10">
#Html.PasswordFor(m => m.Password, new { #class = "form-control" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(m => m.ConfirmPassword, new { #class = "col-md-2 control-label" })
<div class="col-md-10">
#Html.PasswordFor(m => m.ConfirmPassword, new { #class = "form-control" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" class="btn btn-default" value="Register" />
</div>
</div>
}