Another tip: Put the chain on the big ring and wind the crank until the split link is over the front of the ring. Now, from the bottom, work one extra link onto the chainring, making one link “bulge” away from the ring. Move this slack up the teeth until the link that is bulging is the split link. Now tap the sticking-up end of the split link with a mallet. The split link is trapped between the mallet and the chain ring and should undo.
A diagram would be easier but I don’t have one.