I asked elektron and this is the answer:
"No, it’s fine to open it to remove dust. I recommend using a can with pressurized air.
If you however remove the panel completely and disconnect the cables it is extremely important that you attach the cables to the exact same way that they were connected originally. Please ask us if that happens."
Sorry for reviving an old thread, for future reference for others, I was able to remove a hair under the screen of mine by blowing compressed air down the side of one of the track (T1, T2 etc) buttons (Elektron advised to try this way, but that it was okay to open it up if it didn’t work). Only took a few seconds to dislodge it, which was nice as it was doing my head in 
Top tip, ty. I have a spec of dust after a repair and I keep trying to brush it away. 
Brush harder
Really? I’d like to see a picture of this… I own four Elektron products and have never noticed dust or particles underneath the display… I recommend submitting a support ticket… They’ve always responded fairly quickly too me…
I’m putting up with it. I’ve already sent my lovely machine in twice for repairs! (it’s perfect now, other than that :))
Yeah that would drive me insane
If you decide to used compressed air, I’d advice to buy a can of air “special electronics”. It’s not a gadget: your average domestic air compressor produces a lot of water (that’s just the way it works) and you need a VERY good filter and a VERY dry atmosphere to get electronics-grade compressed air. Because it’s very powerful, you can blow moisture even into the tiniest spaces and that will eventually cause corrosion overtime. Moreover, the airjet can propulse a tiny drop of water with such power that it can damage a capacitor or other components. So do yourself a favor: it’s worth the few $$$/£££/€€€
Every device that I repair (including a kind of electron) is always thoroughly blown away from dust.
But besides this, I always install additional dust protection around the perimeter of the screen. It’s usually made of foamed polyurethane. High efficiency with low cost.
