How to pronounce R & RR in Spanish 

Interesting. I actually always pronounce it as “aksessory”.

Even native speakers of English can't handle the spelling!

I'm a native speaker of American English but for some reason I find both the uvular trill and uvular fricative R of French fairly easy (not that my French is otherwise acceptable!). I can to some degree pronounce the Spanish alveolar trill (mainly between vowels, as in "perro") but it's easier if I've had a beer first. (This is not a joke.) I think a uvular trill may be an acceptable substitute for an alveolar trill in many contexts especially if the goal is to be understood rather than to sound completely native. In fact, I gather linguistic historians think the French R was originally an alveolar trill (though certainly by the time of Molière it was an uvular trill). By the way, there are dialects of Spanish in which the trill isn't used, notably in Costa Rica where at least among natives it can come across as pretentious. From what I've read there are native speakers of Spanish who trouble with the alveolar trill. Very young children tend not to use it) and some adults substitute a uvular trill so the difficulty isn't just a matter of unfamiliarity. The uvular trill for RR is also sometimes heard in Basque regions of Spain and in rural Puerto Rico.

Mine is broken. It doesn't work for me.

They do the flapped R, but not the trilled R

It's also found in some dialects of English, most famously and strongly in some dialects in Scotland but also in very upper class British English particularly for initial Rs (as with the initial R in Spanish).