I now think and assume your title asks a much more simple different question, than I assumed by
extract recovery image to get dtbo.img and Vendor_boot.img?
My apologies.
Start again !
You are stuck at this point ?
First unzip the /e/OS Recovery file linked in the section marked Downloads for renoir . The following files would show up in the location where you unzipped the contents of the eRecovery zip file
dtbo.img
vendor_boot.img
This is not as easy as I thought. What is available is NOT an “eRecovery zip” but the latest file is recovery-e-1.14-s-20230819321663-dev-renoir.img.
This link describes GUI methods to open an .img file, but untested by me https://www.wikihow.com/Open-an-Img-File-on-PC-or-Mac.
Please let us know how you get on, there are others facing this issue which seems to me new to our documentation.