Do you want all machines to use this "manual patching" method, or only some of them? If all of them, then you can just change the Default Software Update Plugin Policy (Settings > Agents/Plugins > All Agents/Plugins > Software > Patch Management > Windows). If you want only some of your computers to use this policy, right-click and Clone the default policy, and make the changes to that one, then apply it to a target containing the machines you want that setting to apply to. Modify the "Start Date" to 12/31/2030, then check the "Allow user to run" box. Configure the restart defaults section as well; usually "At end of software update cycle" works well, or you may want Never. You may want to configure the user messages on the "Notification" tab as well.
Probably it will be much eaiser to just have the users go into the Agent interface and click the "Start Software Update Cycle", but you could create a script that executes the AexPatchUtil.exe as well and deploy that as a manual Software deployment (but the user would still have to go into the Agent to accomplish that).