it is time to replace the rear wheel bearing on the old girl, I've been doing a bit of reading and reading about special tools etc, is it possible to do this job with just a press or do I need these special clamps, having said that is is more than like to escape grief if I buy the whole assembly 18 quid verses 52 quid I rather go for the 18 if it a reasonable job.

Haven't done a rear one, but I did the front last year.
I bought the whole assembly, the bearing can be changed but you must be careful as the vehicle uses the bearing to sense the wheel rotation, and if you get it wrong then there are problems with traction control.

I'd go for the whole assembly, and save the hassle.