This is the Cx4 Storm trigger group.
First remove the Magazine catch assembly. Locate the magazine catch spring.
With a pair of needle nose pliers, push the spring towards the rear and pull up to remove.
The magazine catch can then slide out the side of the grip.
This is what the magazine catch looks like when first removed. The metal plate, that latches into the magazine , can be simply pushed out at this time. Take note of it's location.
If converting the Magazine catch for left handed use the metal plate will have to be relocated. The outside slots are used with the 92 FS magazines.
This is what the magazine catch parts look like assembled.