This action is done on your Settings - Admin settings - Numbers page.
How to get to this page
After logging in to PastorsLine, click on My Profile (thumbnail at bottom of left-hand most column, gold box & #1 in image below). Then click on Numbers (Admin) (turquoise box & #2 in image below).
How to release a number
Step 1: Locate the number you wish to release.
Step 2: Hover at the right-hand end to reveal the 3-dot Action Menu (gold arrow in image above.
Step 3: Click on Release (turquoise arrow in image above).
DOES THE HOVER REVEAL AN EDIT INSTEAD?
(Gold arrow in image below)
No problem. Click on the Edit. The Number Details box will pop up:
Scroll down to the bottom. Click on the red Release Number.