Due to how the admin menu works in WordPress, you can’t edit it without either using a plugin and keeping that plugin active, or actually editing the WordPress source code.
If all you need to do is to hide a few menu items, and you don’t need any other customization, one thing you could try is to disable the associated capabilities for the roles that shouldn’t be able to see the menu items. You can use Admin Menu Editor to find the capability that’s associated with each menu: it will be in the “required capability” field. Then you can use any role editing plugin to disable that capability for specific roles. Since role capabilities are persistent, you wouldn’t need to keep either of the plugins installed after making those changes.
However, sometimes the same capability controls access to multiple admin menu items. In that case, it won’t be possible to hide only some of those menu items without also hiding the rest. That would require a plugin of some kind.
