Cut them at the base with a razor or use fishing line...loop line around xenia base and pull each end. Then use super glue gel to glue the xenia to the rock you would like it to be on. Take rock and xenia out of tank...dry off the end of the xenia and the rock...apply super glue to each...stick them together...put in a small container with water from your aquarium for a few minutes to let glue set up...add back to main tank...throw out water from container (don't put it back in main tank)