Put casing back on water softener head

5638 Cypress dawn, San Antonio TX

Description

Hi, my water softener now works as I’ve replaced a circuit board after breaking it. I ordered new plastic casing for around the circuit just to cosmetically look nice. However, I’m a bit scared and don’t have a clack wrench in order to remove the white circular thing in pic #1. So I’m NOT asking to figure out a repair, just asking to get the plastic casing back on the water softener that is in pic #2. Pic #3 is just what it used to look like or look like once out back together.