If you have already a policy package assigned to your FortiGate(s), you can use the Re-install Policy operation. This operation takes ADOM and policy layer information (from the Policies & Objects module) and installs it to the device layer and to FortiGate(s). You can access an installation preview for this operation. If you do not want to install the changes, you can cancel the operation without modifying anything.
For more information, see Reinstall a policy package.