It's very complicated. You undid the cover under the seat and that's it. Great if you were installing the pannier holders but that's about it.
To remove the backrest you need to basically un-mount the whole assembly from the bike. Also, you would have two massive slots where the braces go that would be empty.
I have to agree, should've bought the R3R and changed the handlebars, the seat and foot position instead. That is achievable.