Reg 07 Outback Auto Propshaft noise fault

Please can some one tell me how to change the center bearing on the propshaft and who will change the staked spider bearings (hardy spicer joint) Thy are a bit lumpy .I was told this was normal but thy do not feel right to me .There is no play or bad movement in the spider joint and no red rust marks. Based in Scotland 

Thanks for the help

David