[Kanji Koohii] Change from RTK 6th Edition to 4th Edition on Kanji Koohii?

When I started using Kanji Koohii it asked which edition of RTK I was using and I chose 6th edition. Right now, I'm traveling and would prefer not to have to lug the heavy RTK book around with me in my backpack. Recently, I found a pdf version of RTK 4th Edition online, which I would like to start using instead of the paper copy of RTK 6th Edition.

Without starting all over again, is it possible to switch, now, after completing 400+ characters, from 6th Edition RTK to 4th Edition on Kanji Koohii? If so, please tell me how to do it. Thanks.
Edited: 2017-01-20, 5:24 am by ファブリス
I think there are no problems in changing editions. Go to "Account and settings" under your user name in the upper menu. From there, "RTK edition" in the left sidebar. You can read there the nice explanations Fabrice wrote for us: the biggest issue you'll encounter is the change in the navigation order for the characters you already have studied, and in the case you struggle to find one of them, you could always revert the change momentarily.
Thank you @faneca! That answered my question completely.
Bear in mind that a few of the kanji and/or keywords were changed between editions. You can learn all about that here in the supplement to the 6th edition.
Edited: 2017-01-17, 6:48 pm