Disco 1 Aux belt tensioner

Terrible squeal coming from tensioner so decided to replace it. When the tensioner came out the bolt came out too. Anyway, put it all back together, new tensioner and belt. Pulled on the tensioner to fully seat the belt and the whole thing came off and pulled the bolt straight out too ripping the thread with it.
Any ideas on what to do next?

Helicoils?

I've never used anything like that before; at best I'd be apprentice mechanic. How easy / difficult is this to do?

It's fairly easy if you have a bit of mechanical know-how.

The kit comes with a tap for making a new thread an inserting tool and some stainless steel helicoils. The idea is that the damaged hole is tapped out with a new thread and it is then lined by screwing in the helicoil using the inserter tool. Once the helicoil is in place, the little piece at the bottom is snapped off so that the bolt can be screwed into a new thread.
I have found that you probably won't need to drill out the hole before tapping it if it's aluminium you're working with, but you might need some cutting paste or lubrication for the tap.

You buy a helicoil kit to match the size and thread of the bolt you want to use.

you need an m10 x 1.5 kit there are several makes recoil is one i use,but halfords do one
https://www.google.co.uk/url?sa=t&r...-1-5mm&usg=AFQjCNF1wf7EZ7Ac5Ep6n5trkRu6LOZYpw

James, Brian, thanks for the advice. I'll check out the link you gave me James. Don't fancy replacing the whole housing

The problem is getting a drill in to clean out the hole to re-tap it for the Helicoil. If you do not get the hole size correct for the tap it is easy to tear the aluminium out rather than tap the new hole. Otherwise not too difficult, but make sure you get the tap square as you cut the new thread.

After James' suggestion, I've been looking at this.

http://www.ebay.co.uk/itm/231436746535?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

YouTube has some decent videos relating to it so I'll be giving it a try soon.
Thanks all.