Unless you're very lucky, some electronics and pc board repair is quite likely - at some time or another. I would say start with the tech docs and PinWiki if you want to learn some basics about how to troubleshoot this problem. There really isn't an instant solution video out there, as there can be all kinds of problems that cause the symptom of a blown fuse. One example is a stuck switch can cause a blown solenoid fuse if a coil is locking on. Read on in the links below.

http://pinball.flippers.info/system6resources.asp

http://pinwiki.com/wiki/index.php?title=Williams_System_3_-_7

Focus on solenoids numbered 1 thru 8. One or more drive circuits seem to be locking on. With the connector removed so that you don't blow any more fuses, replace fuse and use a DMM, ocilloscope, or logic probe to determine which one(s) are suspects.