UK Lampshade modification to fit US Harp mounting

I couldn't find any help on-line showing how to convert a new UK lampshade to fit an existing US style harp and spider mount. So I had a go myself and recorded the steps of the process.
Disclaimer: If you try this for yourself, no responsibility is assumed for any damage caused to person or possessions. Remember to use tools safely!

[@tommy4176]

Very helpful. And very clever. Thank you for sharing! Hopefully you have helped me salvage several very expensive lampshades!

[@mehsansaeed]

Very useful. Thanks.

[@pamelalulu26]

I had the same problem. I did a lot yt and found an easier way remove the inner plastic piece and just add washers.

[@NakeanWickliff]

Do you have a link?

[@marymcghee3023]

My lamp does not have harp

[@TwoPartyIllusion]

Cad... LOL😂