Remove the skimmer basket from the skimmer you are not using for your suction line. You want to vacuum the pool with the skimmer closest to the pool pump.
Plug the skimmer with a #10 rubber plug inside the suction fitting.
Immerse your pool line into the water and allow it to fill.
Attach a skimmer disk to the end of the suction line.
Remove the skimmer basket from the other skimmer, and attach the suction line to the bottom of the skimmer using the disk. Push down to attach.