Menu > Setup > Locker banks > select the one you will need to do: 

 

Step 1 - Update the records 

  

From the 3 dots, you will be able to Assign a bank to lockers, Clear a bank from lockers and Export 

 

Step 2 - Clear the Locker bank 

 

Step 3 - Assign lockers 

 

Finally, when you go in Lockers, you can see those lockers were assigned to the new students and you can export the data of your Lockers bank / Lockers