SharePoint Online update list item

I have custom list in one site collection which have multi line field (RichText Field). It have images path for that site collection.

Now when I migrate this list to another site collection. Path for the images is still showing old site collection. So I thinking to update those path.

I was thinking to use PowerShell command to update those path. Kindly let me know any other easy way to do that.

Please give me sample PowerShell command to update list item in my scenario