Yeah, as far as I can tell NuMenu4U has died but a few sites still have it available.

It was developed to allow menu re-encoding when converting DVD9 to DVD5 with the Big 3 method (before programs like DVD Rebuilder).

It's a bit of a Rube Goldberg that takes some effort to get working and configured. The only reason I have it at all is because during re-encoding it has the ability to convert PAL to NTSC.

Frankly, if the author expanded it to re-encode the movie as well it would have been indispensible.

The other negative is that it uses Sonic Scenarist for rebuilding the disc, but a pay/registered copy can use Muxman Pro. Since it's dead-ware, you are stuck (unless you get yourself a crack for it).

It's a bit awkward to start. Look at Doom9's preparation guide: http://www.doom9.org/mpg/big3-preperation.htm#NuMenu4u

From there you can try the NM4U's Wizard to get going. I can't remember actually seeing a guide for the program unfortunately.

Just make sure you go to the menu "AviSynth" and check "Convert Menu Format (PAL -> NTSC / NTSC -> PAL)". (There's also an option to re-encode all assets, that's on by default, which of course you'll need as well.)