Here're the detailed steps on how to delete partition in Partition Expert:
Launch the Macrorit Partition Expert, you'll see all detailed information of the partition and disk. If you want to check some terms related, here is the difference become delete and format. Now you can see the disk map loaded.
Select the partition/volume that you want to Delete, right-click or use the guide operations listed on the left area to Delete volume.
Click OK to add the pending volume creating operation.
In the end, Click Commit button, the changes can take effect, then volume you deleted then will become an unallocated space, which you can use to extend partition or resize other partitions