1) 
2) Search for Disks.
3) 
4) 
5) Then select the partition to be renamed to the right under Volumes
6) Click on the little block / stop icon to unmount the partition
7) Click on the gear icon
8) Select the option “Edit filesystem …”
9) Enter the desired name here in the Label field.
10) Press Change
11) Press the triangle / play icon to mount again