ya theirs a cover over the nut that holds the wiper on, the cap just pops off and I think the nuts 1/2" or 15mm(cant remember).
Several push pins hold down the large plastic cover under the wipers(where the motor and linkage are). You'll need in thier to see whats broken or poped off.
Try lifting the wipre all the way up, where it normally goes, and see if it doesnt catch, mine hav done this same thing is heavy snow, and usually it'll catch and start working

Other wise you might need some parts.....