Not a video but seems straightforward.
Factory
service manual here
http://www.google.com/url?sa=t&rct=j...O5Ec7FOpt7nSZK
The problem is setting the tension without the tension measuring tool.
If you can borrow or rent one, no problem, if not there may be a deflection-based procedure for setting the tension; I unfortunately don't know what it is, beyond measuring the deflection previous to removing the old belt and duplicating it.
If you can find a
Perkins Prima M80T manual, which I believe is the same
engine, they may have a deflection-based method, or someone who works on these engines regularly might be able to help...