Copy and Paste the following Code into the Form Module with appropriate changes to refer the Controls correctly:

Code:
Private Sub ServiceType_DblClick(Cancel As Integer)
Dim getval, rst As Recordset, bkmark As String
Dim bkmksave As String

Me.Refresh
bkmksave = Me.Bookmark

getval = Nz(Me![ServiceType], 0)
If getval = 0 Then
   Exit Sub
End If
Set rst = Me.RecordsetClone
rst.MoveFirst
Do While Not rst.EOF
    rst.Edit
    rst![ServiceType] = getval
    rst.Update
    bkmark = rst.Bookmark
    Me.Bookmark = bkmark
    rst.MoveNext
Loop
rst.Close
Me.Bookmark = bkmksave

Set rst = Nothing
End Sub
Enter the required change of Value in the ServiceType field and Double_Click on the field to make changes to all the records and come back to the record where you have made the change initialy.

You can see the changes happening on all the records one by one.