Yeah that’s quite funny. A way to do that is to copy the tools folder to another place (let’s say C:\temp\). Then direct into the C:\temp\tools\bin\, open the cmd prompt there and run your update commands as such:
sdkmanager.bat --sdk_root=sdkRootPath --command
Where sdkRootPath is path to your original SDK folder (C:\testinstall\sdk\). Once that is done, delete the C:\temp\tools\ copied folder.