With due deference to Paul, who is a whizz with find and replacement strings, I don't think this one does what you intend. Nor is it entirely clear what you want to remove and what you want to keep.
From your description I assumed you wanted to keep the IMEI line and the NCK line and remove the other two lines
OR
Keep the IMEI line and the NSCK and SPCK lines and remove the NCK line,
so in the following macro I have provided code options to do either -
http://www.gmayor.com/installing_macro.htm
Code:
Sub RemoveParas()
Dim oPara As Paragraph
Dim oRng As Range
Set oRng = ActiveDocument.Range
With oRng.Find
Do While .Execute(FindText:=Chr(11))
oRng.Text = Chr(13)
oRng.Collapse wdCollapseEnd
Loop
End With
For Each oPara In ActiveDocument.Paragraphs
oPara.Range.ParagraphFormat.SpaceAfter = 0
'Option 1 ________________________
'If Trim(oPara.Range.Words(1).Text) = "NCK" Or _
Trim(oPara.Range.Words(1).Text) = "SPCK" Then oPara.Range.Delete
'-------------------
'Option 2
If Trim(oPara.Range.Words(1).Text) = "NSCK" Then oPara.Range.Delete
'--------------------
Next oPara
End Sub