Replacing Aux Drive belt tensioner

I have a FL2 TD4 and the belt tensioner has cracked and failed and needs replacing.

I've got the plastic cover off under wheel arch and can see I need a large torx bit, does anybody know the size as i am going to have to buy or borrow one.

Also is this just a case of unscrewing this bolt and then refitting ?

I see on Ebay there is a pin, do I assume I pull this out when I have fitted the new one to tension everything back up again ? Its £30 delivered is that good ? or is it gonna be a cheap useless one ?

Anything i have missed ?

Many thanks for any replies

i think the pin stays in until everything is fitted and done up tight, then you pull it out and the tensioner the unwinds. this is a one shot deal, and if you pull the pin out before it's fitted, it's good night vienna

also, with all thanks to the good Hippo, here is a link for the workshop manual for your vehicle, which you can download:

http://www.landyzone.co.uk/lz/f69/freelander-2-repair-maintenance-manual-247438.html