Fairly simple diy job and done it myself a couple of years ago.
Buy the oil and a 'kit' from somewhere like here:
https://www.ebay.co.uk/itm/183076581177
Easier with a flexible drinking straw to access through the top up point to draw almost all of it out. No supercharger removal reqiored.
Replace with same volume extracted.
There a few threads about it on this and of course a Google search will help
