Check this site:
http://homepages.ihug.co.nz/~miles.j/shape.html#dl
I did it with a PC and Basilisk. I made a bootable hardfile with System 7.5.3 on it and transferred that to my Amiga with FTP.
The guide for PC basilisk can be of help too:
http://os-emulation.net/basiliskII/system753_tutorial/