Help with one model

[Flyethemoon]

Hello

Can somebody help me please, because i got one problem
Ive wanna cut this element from model (Model can be used only in XNA/XPS Lara program)

So ive downloaded blender and XNA/XPS plugin for blender and instaled, and choice edit mode after import model but there no knife button like ive saw in some screenshots on google.

You can download program here
http://www55.zippyshare.com/v/GjzNLcMz/file.html

Model
http://oo-fil-oo.deviantart.com/art/PYRRA-SKIRTLESS-443158502

and Plugin
http://johnzero7.deviantart.com/art/XPS-to-Blender-2-7x-Blender-internal-the-easy-way-489500171

PS I got premision from author to edit this model BTW.

[Richard_Marklew]

but there no knife button like ive saw in some screenshots on google.
Show us what you see

You don’t need the knife tool. Just select the vertices you want an then press P to separate them into a new object

[Flyethemoon]

Its not work for me i just highlight what i want press P and that still are intact.