You should be able to do the move in a couple of hours, if you practised on a testboard first.
Never start with the hacks. If you run into any problem with ImpEx, you can not get support if your board has hacks. Make a good backup before installing any hack.
Thanks mate.. Yeh.. i know the basics of istalling a hack (i have worked on phpbb long enough) and in phpbb its a hack for everything.. Even for a attachement its a hack.. So i do know the basics like the need to take backups before installing etc..