I did this job on mine last weekend. The symptoms were exactly the same as yours.
I got one with the part number XRC100390 from ebay for £23 posted.
Care needs to be taken because the first step is removal of the airbag on the steering wheel. The advice in Haynes and from the Land Rover specialist is to leave it 30 mins after disconnecting the battery before removal.
The rotary coupler will do 2 1/4 turns either way from the central position so set it central before refitting. You need to know this if you bought a 2nd hand one like I did.
Lastly check you have free steering lock to lock after you put everything back together but before you drive off.
It was quite simple job in the end.
This how-to is the same for the Freelander.
http://mgf.ultimatemg.com/group2/DIY/steering/index.htm