When you’re done with your board(s) you can store the remaining paste for later use, the process is the same as attaching the motor but in reverse:
1. Unlock the syringe by twisting it counterclockwise. Line it up and press the left knob to lift it up.
2. Once it clears the motor adapter you can turn it by hand.
3. For storing, remove the tip and put both caps top and bottom. Most manufacturers recommend storing in refrigeration, you can do that now.
If you don’t want to waste the paste left on the tip, you can also leave it on and cover it to prevent air from reaching the paste. You can use food wrap, scotch tape, a drop of hot glue, silicon, play-doh, a strand of wire, etc basically anything that covers the hole.
For long term storage I still recommend putting the cap, read the Cleaning and reusing section for help on how to clean the tips and barrel.