I used those plates once.When i bought them new i found the centre hole was slightly too small so i took the excess paint off with a dremel.If you have just the plate and the strut with no spring on it that plate should just slide down the shiney shaft of the strut.If it sits on top the hole is too small.The wider part of the shiney shaft which starts just below the thread goes inside the bearing,the cap goes below this.That bearing is not moveable when it's seated correctly.
In your opening post you have 2 pics.The one on the left shows the bearing upside down.