Using GRIPit with a Lobster Clasp
Insert the V-shaped tip into the jump ring next to the clasp, then place the nail-shaped tip on the clasp lever.
Place your thumb on the slider and your index or middle finger on the top dome, then push the slider forward to open the clasp.
While holding the clasp open, insert the necklace end ring into the lobster clasp, then release the slider to close the clasp.