How doI make DVD w/ svcd video dvd audio?

[PROJECT MAYHEM]

OR PUT SIMPLY HOW DO I SWITCH THE VIDEO OF A PRE AUTHORED DVD WITHOUT LOOSING SOUND OR MENUS ?

ok I know its ameture night
in plain language..my freind authored a dvd...great 5.1 sound but picture isnt great at least not as great as the quality of the one i have on vcd...so what i was trying to do is take my picture and put it to his sound a nd reburn to dvd
the dvd menu has ifo and bup files as well as the mpeg [actually that would be 3 mpegs.titled vts-01-1,vts-02-2 and vts-01-3]..i did what you said and demuxed one is picture the other ac3

just like the 3 chapters on the dvd theres 3 parts to the vcd...but from what ive seen they arent exactly slit at the same exact point..pretty close though...so i imaging i has a little editting to do?

iv e also used [s]vcd2dvdmpg and split the sound and image file out of the vcd...where i noticed it doesnt look too shabby but theres a empt y green field at the end instaed of the picture taking up the frame....uuuhhhh... any helpfull tips...and sorry to keep disturbing u
thanx again

[PROJECT MAYHEM]

hellow?