Canned air outside.
Don't use a vacuum, the static build up could/can damage electronics or cause them to operate in a fashion not intended. But, usually you can get away with using a vacuum if the system doesn't have any IC or anything digital.
Also, get some Deoxit from CAIG Labs. Spray all the connection points and plug in and unplug the connections several times. You can spray down the circuit boards if you need to get extra stuck on dust off. Just don't rub after you spray. I've seen the higher concentration Deoxit take writing and some traces off of old boards if you rub/scrub it.
Also, a clean cotton cloth or I guess paper towels to help wipe everything off once you are done. Put, don't rub or do an abrasive 'scrubbing' motion if you've put the Deoxit on. You could use a different type of connection cleaner, but Deoxit is the best one that I have used, and I've ordered and tried everyone from Tessco, Hutton, PE, MCM, Fastonal, & a local company Dickman Supply.