Not difficult.

They're stoloniferous. The underground portion of the stem is a little thinner than the aboveground part, and usually not more than three or four inches down. It will run back towards the spot where they appeared last year, with a few bulblets scattered along it's length. Dig down carefully beside the current years stem to find it and trace it backwards. When you've uncovered enough snip it off then dig up the main bulb and relocate, planting it at the same depth you found it at. Just give it a little TLC after replanting and it shouldn't even notice it's been moved.