If a random stranger can remotely hack your router, I wouldn't be confident that any settings change will secure it. The router is garbage and needs to be replaced, which is easily within the understanding of an average person.
That view is a bit naive. If the problem with a router is that the router is shipped by default with a known back-door or with insecure settings, that does not mean that "the router is garbage". It points to a deplorable lack of wisdom on the part of the vendor, but does not necessarily imply that the only solution is the pay for a replacement.
