Push the seal roughly into position.
Start at the top getting the groove securely in.
Gradually work around making sure the groove in the seal goes fully in.
Use one hand on the inside & one hand on the outside of the seal.
When the seal is on check all around to see if the gaps are all even.
Then fold the seal inwards gently.
Undo the circular retaining clip as far as possible before fitting it on.
Bernii, February 2011