Hi
Please download this script and run it in the power shell according to the link.
Change Windows Store apps default installation location in Windows 8(PowerShell):
https://gallery.technet.microsoft.com/scriptcenter/Change-Windows-Store-apps-465af642
To run script in power shell with Windows 8.1 ,you may need to configure this group policy ”Turn on Script Execution ”.Run gpedit.msc to open the group policy and navigate to this path : Computer Configuration\Administrative Templates\Windows Components\Windows Power shell\ Turn on Script Execution
I hope this information above can help you.