Join Date: May 2006
Location: New York, London, Sydney
Programs: United GS/2MM, DL*P, VS*G, AA*EXP, Avis CHM, Hertz Platinum, Sixt*D, HH*D, HGP*P, Starwood*P
Posts: 9,881
Theoretically, any change whatsoever to the first segment. Literally: any change, will cause a reissue AND a reprice. You might get away with a mere date change, possibly, maybe, but that would be the absolute best you could do.
Technically, RTWs are non-refundable tickets because there is a provision in the penalties section about a penalty (duh) for refund. It's $125, IIRC. So, for your purposes, it is practically refundable -$125.