Push fit flexible fittings

[dugit]

I have just bought a 15mm by 1/2inch by 300mm flexible connector with valve which I am going to connect to my wc system.
I am a little concerned as it is the first time I have used a pushfit connector to copper pipe.
A rather silly question I'm sure do you just push the copper pipe in softly or hard, also how do you release the copper pipe if you have need to (I see a hexagonal nut at the push fit end) ?

 

[bengasman]

The hex nut will be the half inch side.
Instruction leaflet should tell you what to do, failing that look at the manufacturers website.