Hi Toytuff.
In my experience take off top tree and top and bottom covers will come off.Take care they can fall off.The top cover sits in the chrome ring you want to replace.
On reassembly put the bottom cover,rubber and ring on the lower tree slide fork leg in and refit top cover,Pinch up the lower bolt then do the same for the other side then refit top tree and adjust as necessary.
Hope this helps
Regards