Table with 449 Million Records

Hi All,

I have a table with two columns and 449 million records. 

Table Structure :

Create table EmployeeList (

Id  INT,

Divison VARCHAR(250) )

I have a chance of two same ID's with different divisions, In this case i need to concatenate those both records into single record. I am trying with Stuff and  XML path to join the values. I didnt get any output even after running for 6 hrs.

Rohan