[600MRG] Icom IC-735 600m transmit mod question

[Mike-WE0H]

Over the years I have read about some of the guys using modified IC-735 
rigs on 600m and other Experimental bands. I finally broke down and 
bought one of those radio's. It is still on it's way but now I would 
like to know what the mod is to make it transmit on the 600m and below 
bands. I know about filtering and so forth, just need to know the 
specifics or what the guys have to say about the rig.

Thanks a bunch,
Mike
WE0H
WD2XSH/16
WD2XGI