Not sure how many modelers use this type of plug but i have used them over the last couple of years and they can be a real pain trying to get them apart especially if the are inside the fuse. A good pull and you can usually damage something for sure or if you're tempted to pull by the wires it can be terminal as well.
I have a remedy that works for me and it only involves drilling two 1.5 mm holes about 2 mm deep and then i just use circlip pliers to push the plug halves apart. The 3 photos will tell the story. Hope it's of use to someone.