Upgrade istio 1.4.3 Helm to istio 1.5 istioctl

I am using istio 1.4.3, this is installed using helm and I have 3 ingress and 1 egress GW in the istio-system namespace. Is there any steps to upgrade from istio 1.4.3 to istio 1.5 using the istioctl while keeping all my GWs.