Well they came out easy enough, size matters with spanners
https://uploads.tapatalk-cdn.com/201...57c67a4089.jpg
But not good,
https://uploads.tapatalk-cdn.com/201...973bef399b.jpg
There’s only about 1.5 threads inside and looks rather as though these plugs have been forced in rather then having the hole tapped first.
I’ll ring the engine shop but gut feeling is that there should be drilled out to accept a proper plug.

