Login to your account that is associated with your hotspots via Helium World. Once you are logged in and viewing the homepage, head to the Hotspots tab.
At this point you should have a searchable list of all of the Hotspots associated with this account.
Find the Hotspot that you wish to change the location of and simply click on its listing, you will be presented with the Hotspot overview, along with your management options, click on the gear icon and select Reassert Location
Select your new location and confirm it.
And lastly, confirm your transaction.