Removing sound from a MJPEG .mov file

If I already have the file rendered, and want to remove the sound without having to open the original mpeg, can I just load into CS3 and then export again without sound. Do I need to do 100% on the 2nd time around, or will 95% be okay again? Any input please

You will lose some quality re-rendering a compressed file. How much depends on the quality of the original MJPEG. If it contains subtle vignettes, your clip may incur some banding. Better to go from the original, or if you have to recompress, set it to 98% which will give you best quality but still a smaller file size than at 100%

If you have QuicktimePro, you can open the clip in QuicktimePro, Select 'Show Movie Properties' from the Window menu (or use cmd+J ... maybe ctrl+j on Windows), select the 'Sound Track' and click the 'Delete' button. Then cmd+s or ctrl+s to save... or do a save as, just in case you're worried about overwriting your original render.