You'd just need a wheel bearing, unbolt hub, unbolt disc brake, remove brake carrier, remove hub, push out bearing, fit new bearing. That the short version, more details in this link How to...... Change the front hub
You mention its an advisory and mot inspector indicates it has slight play, before looking at changing your wheel bearing check the wheel nuts are tight, I had a similar advisory a few years back on one of my TF's, turned out my wheel nuts were not as tight s they should have been...also seen this on a mazda bongo I had, bought two new wheel bearing as steering was all over the place, went to change them wheel nuts were not tight....always check wheel nuts are tight, especially if you've had tyres changed or other work done either by yourself or someone else.
Dert posted whilst I was writing the epistle below, and he makes a VERY good point, which I should have thought of. I am ashamed to admit that I once presented my kit car for an MOT, and was told with a smile that they had found play, thought "wheel bearing", then checked wheel nuts and realised I had made a schoolboy error!
I would suggest that : Wheel Bearing Kit - RFM000050P - Aftermarket
Should solve your problem, or least get you started. This is available from Rimmers for £25.80. The OEM version is a different part No. and a lot more expensive. Unless Rimmers are buying "cheap & Nasty" bearings, which seems unlikely, I doubt if (in this case) O.E.M. is worth the extra. Others may have a different opinion. Make sure you follow workshop manual procedures regarding grease, correct torque preload on the stake nut etc. I have (on a Vauxhall Magnum front wheel bearing set-up), encountered problems with bearing inner races rotating on, and wearing the surface they were mounted on. This is unlikely on the Rover set-up, but if it HAS happened, you will also need to replace the drive flange assembly. This is somewhat more expensive, so do not buy unless and until you are sure it is U/S.
You will need to remove the brake calliper to get at the hub & bearing assembly. If you have a friendly garage, get them to press-out the old bearing and press-in the new. Obviously, remove the circlip(s) first! Good luck!