You can edit configuration of existing virtual machine by following steps mentioned below:
1) Login to VPS Web Management Panel.
2) Click On Virtual Private Servers - Refer 1.png
3) Click On VPS name - Refer 2.png
4) Click On Configuration - Refer 4.png
5) Click On Edit Configuration Button - Refer 5.png
6) Enter New Details (RAM / CPU / HDD) and Hit Update - Refer 6.png
1) VPS Disk Space cannot be compressed. You can only expand it.
2) You will need to expand disk space through above steps and thereafter contact our support department as actual expansion needs to be handled from backend.