hi euro car spares or GSF what engine is it and does it have air con?
Where abouts in the country are you please ?.
There are a few youtube clips on bearing replacement. It's not too difficult or expensive to do and the removed bearings will have a stamped reference number on the rim if you are unsure of the type and size
One example - https://www.youtube.com/watch?v=RhFoFSe1A3U
Cheers Spike
PS. If it has the freewheeling pulley first check it's not that which is making the noise
OOOPS also look at getting the idler (big sprung unit) as they can lead to a failed pulley and vice a versa cheers mike