Some armour can be accessed by a zip at the base of the jacket, situated under the flap where the connection zip is, this allows access inside the jacket - any garment without this please use the instructions below:

First step is to unzip any removable linings from inside the jacket

On some jackets the lining will be zipped into the sleeve, or on a popper also 

Pull out the mesh lining slightly on the arm which will reveal a Velcro tab and the armour pocket 

The armour can then be accessed via the pocket and removed