First get hdinst.lha from Aminet.
Then get WinUAE 1.4.6 from
www.winuae.net
Now run WinUAE, go to Quickstart, select A500 and click on Set Configuration.
Go to Hard drives and click on Add Hardfile. Enter 100 into the size field and click on create. Select a name and click on Save. Click on Enable RDB Mode, then on Ok.
Now click on Add Directory or Archive, click on Select Archive, point it to hdinst.lha and click on ok.
Go to floppy drives, click ... next to DF0 and point it to your Workbench1.3D.adf
Go to Configurations, enter a name and click on Save, then click on Start.
Wait until Workbench has loaded, then open hdinst.lha, HDInstTools and drag HDInstTools to Ram Disk. Open Ram Disk, select HDInsttools and choose Workbench / Info from the menu.
Scroll down the tooltype until you see LANGUAGE=locale. Change this to LANGUAGE=deutsch. Scroll further down to MODE=manual and change it to MODE=auto. Then go down to ;DEVICE=scsi.device and change it to DEVICE=uaehf.device (note the removed semicolon). Don't forget to press enter after each change.
Click on save and run HDToolbox. Double click on the HDD and select Yes (Ja).
Follow the on-screen instructions.
That's it.