Bit of a thread resurrection but I have just been doing this job on my Mini. I found an easy way to remove the needle roller bearing using an old front swinging arm spindle. Putting it through the hole and pushing it to one side so it sits under the lip of the bearing then tap it with a hammer. It is a bit short so need a punch on end of spindle. Bearings popped out a good un but getting the tube out was a vey messy activity.
Classic Mini the project that keeps giving. Thought it would be a good idea to use soft brush to try to remove some of the crud inside the arm and it broke off. Now got to prepare myself for a bit gynacology to remove it.