Aux belt tensioner replacement

Afternoon good gents and lasses

I've searched and searched to no avail! Right my aux belt tensioner failed on me the other day, the bearing collapsed out the the blue. I've got one on order and apparently it comes as a new assembly ie an arm and wheel.
So far I've managed to get the old wheel and bearing off the tensioner arm, but bugger me if I can work out how the tensioner arm comes out the block? Don't want to damage it as it's working fine, but if I'm paying for a new one, I wouldn't mind replacing it. Failing that I'll just pinch the wheel and bearing off the new and fit to the original arm.
Any advice would be appreciated? It might become apparent when I've got the new in my hand but the Haynes manual is useless

Cheers

It unbolts

In what way Thor? Does the right angle arm just unscrew from the block against the spring?

ChrisHughes said:

In what way Thor? Does the right angle arm just unscrew from the block against the spring?

Click to expand...

http://www.google.com/imgres?imgurl...a=X&ei=KZZNUsGFAqWGyAGZ5oCoBw&ved=0CEIQ9QEwCQ

Looks like 2 bolts holding the bracket to the motor to me

Wrong style tensioner, possibly off an L series or V6. I'll post a pic later, but cheers