Wd-40 works great for cleaning corroded electrical contacts. Use that in combination with a dremel with a rotary brush that will fit in the fuse slot just like noneck did.
You can back the center bolt out of the fuse block from the firewall side and pull the harness off the firewall. The connection prongs sticking out can be cleaned by some 350 grit wet or dry w/wd-40 or you can take a pair of pliers and gently squeeze the prong and then pull the wire out from the other side. This will let you file/sand/scrape or whatever to clean the prong. To make sure it stays in when you put it back, use a thin flat blade screwdriver and gently open the prong.
Dave
You can back the center bolt out of the fuse block from the firewall side and pull the harness off the firewall. The connection prongs sticking out can be cleaned by some 350 grit wet or dry w/wd-40 or you can take a pair of pliers and gently squeeze the prong and then pull the wire out from the other side. This will let you file/sand/scrape or whatever to clean the prong. To make sure it stays in when you put it back, use a thin flat blade screwdriver and gently open the prong.
Dave