How to change synch locations...

I want to change the Synch from Dropbox to iCloud - is there anything special to do or to watch out for?I don't want to screw anything up. I'm humming 1Password on 2 Macs, phone and iPad, but Dropbox will only let me synch to 3 out of the 4 without a paid subscription. With iCloud, theoretically I can synch all 4.

Thanks,

Martin