Slash and Spread
Turns out, this form of dart manipulation is exactly what it sounds like. Start by tracing your original pattern piece, so as not to mess up your master copy. Once the tracing is done, cut out the dart.
Next, determine which of the possible locations you want for your new dart. In my example here, I opted for the shoulder tip dart. Draw a line from the new dart location (shoulder point in this case) to the dart point. Cut along that line.
That’s the slash part of the process. Now using the dart point as a fulcrum, spread your new dart, while closing the old dart. Tape in place.
This works for ALL of the possible dart locations. Trace, slash, spread. That easy. If you want a quick and dirty sanity check that all the ease has been relocated to the new dart location without making the mock up, the dart you cut out should fit in the new dart location.
But you should still totally make the mock up to confirm fit. Always best practice with fiddling with a pattern.