locate the first one and open it.
say you downloaded the simpsons movie, and the files are
The-Simpsons-Movie-DVDQuality-PartX.rar
X = a number, 1 - 83 in your case
locate either Part1.rar or the .rar without any number (The-Simpsons-Movie-DVDQuality.rar"
once youve located either of htose, double click it and extract like normal, the entire movie will extract from all 83 rar files...well...hope its the movie...if not then theres alot more you have to go through to watch it -.- but lately (the past few years) most movie rips are simple .avi once extracted.