Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
This video briefly describes how you first
1) unscrew all the screws from the bottom, and from the sides.
2) then the back part can be lifted back from the key bases, and the sides of the ranks of keys.
3) and that allows access to the key mechanisms and the key switches.
is the video. The beginning particularly is what you'd need to look at.
Note: That is not a KR series. It's a smaller model by Roland. I suspect it does not match yours at all.
Advice about the KR series, states in brief, take the back off first, carefully.
I understand, and I admit I had severe doubts about the quality of my answer.
I simply could not find any better information. The hint I quoted at the end, refers to a KR series full-size piano-style instrument... but it's the most I could definitely find.
Shall I search further, or would you rather wait for a better-informed Expert to be available for this question?
I doubt I shall find more info on this question, so I have Opted Out, in favor of an Expert who knows the case disassembly procedure for the Roland KR-series or (specifically) KR-1070 grand piano.
(Opting Out does not cut off communication. I will still respond to an further posts of yours to this question, as needed.)
Thank you for your patience.
Hello. Thank you for coming to JustAnswer.
Sorry for the wait. My name is Michael. I will be helping you with your question today.
Please let me know if there as any additional information that you think might be pertinent to your question. If not, I'll provide the best answer I can based on the information you've provided. You can always reply with additional information or questions at any point during our conversation, and I'll be happy to continue helping.
OK. Thank you for coming to JustAnswer.