I'm not claiming it's impossible - just much more difficult than most other pistols. The requirement of both a .22 case (or other spacing device) and a pin-punch in my book make it a not-so-easy disassembly (after all, my SIGs just require locking the slide back, flip a lever, let the slide move forward and off).
Reassembly is even more difficult in my opinion, with the juggling of the recoil spring, guide, and cap. Heck, even Rohrbaugh suggest the use of a channel-lock wrench for that.
It's not something I'd mark down as a deciding factor for a buy/don't-buy decision, but the R9 is a lot more difficult to assemble/disassemble than other pistols.