Are they rubber Hogue Bantam? If so you need to spread them apart at the base far enough to clear the stock pin. Then slide them up and off the frame. Hogue provides a tool to spread them.
I watched a youtube video with a person named Hogue using his tool and credit cards.
I removed the grips using wood wedges.
Installed Crimson Trace LG-305, they are longer and deeper.
The dimensions make for a much more comfortable grip on the gun.
Nice choice. I put Ct 305's on my 360PD. Irregardless of the laser feature, the grip, shape, size and materials made a world of difference in comfort and control.