@danbarkley 

That's easy enough to do.  During the setup process after you link the extender to your Host network you will see a screen with the Extended network names on it.  Just click a name and remove the _EXT.  Take care though as this does bring its own possible issues.  Because you will have two APs broadcasting the same SSID you may have some connection issues.  These mainly happen when your devices are inbetween both APs but still with in Range of both.  If you encourter intermittent connection or devices not connecting at all you will either want to relocate the extender or give it a unique SSID.

@2006yamahar6 @danbarkley 

YamahaR6, firstly you are simply assuming that is what Dan is trying to do.  Unless you are associated with Dan personally and know more about his particular situation, but since he registered in Chile and you in the United States that seems unlikely.  When a Range Extender is setup in normal Range Extender mode it has the abilty to generate its own SSID or "Clone" the SSID of the router.  Based on his post this is what Dan was speaking about and why my answer was crafted in the way that it was.  

OneMesh is another setup entirely and not only requires the Range Extender to be compatible but also a compatible rotuer.  The RE305 compatiblity with this service is dependent on the hardware version.  As the Splash page for the RE305 correctly shows only the RE305 V3 and above are compatible.  Right now only the V1 is sold in the US so that is going to be why you don't see OneMesh available.  It is not compatible with Version 1.