Exactly as Jack described it really. I have used a grinder in the past on a drop link,but it's very tight for space and not really the tool for the job. A nut splitter is the other alternative
Best thing I did was replace the links with Mayle HD ones,which tend to last longer than the typical 12 months that the cheapo ones do.
I'm always amazed how quieter a Multi is with new drop links!