Install / Preparatory steps xperia Z4 Tab

sorry for asking my question in this thread. But there are probably still too few xperia Z4-Tab users, so that I cannot get any answers in the support thread.

I am not successful in Preparatory steps 8 & 9. I can load and save the FIle SW_binaries_for_Xperia_AOSP_M_MR1_3.10_v13_legacy.zip but after unpacking I cannot find the file: SW_binaries_for_Xperia_AOSP_M_MR1_3.10_v13_legacy.img but a complete directory tree.
How can I generate the img file from it? Is the link in the instructions really correct?

I would really like to install UT on my tablet (and also test it), but unfortunately I already fail in preparatory steps 8 & 9. Please help me, because I assume that you have successfully install UT on your Z4-tablets.

Hope for Your help ...

P.S. Thanks for porting this tablet, because I'm a ubuntu user for over ten years....

The support of the xperia z4 tablet is like an early Christmas present for me. But unfortunately I fail because of the installation or the preparatory steps.
(https://devices.ubuntu-touch.io/device/karin/)

It works until step 8 without any problems. But at step 9 I have profound questions.
When I unpack the archive / firmware file (https://developer.sony.com/file/download/software-binaries-for-aosp-marshmallow-android-6-0-1-legacy/), I don't get a firmware file but a directory with many individual files. Of course, I would have expected only a single * .img file, which is flashed in step 9.

Who of you managed to take this step successfully? What are the details in step 9?

Additional question, if I can manage step 9: In which mode (Flash / Fastboot / Recover) does the Xperia z4 Tab have to be for the following installation with the UBports-installer?

I would be a happy person if I could make it to Christmas!

@Guf
Many thanks for your response. However, I am amazed that you have never tested these preparation steps yourself. Your suggestions with TWRP are also new territory for me. Now I have seen in the new version of the UBports-installer (0.8.5-beta) that there are no more preconditions. So I tried to install ubuntu touch on my Xperia z4 tablet. Unfortunately the installation got stuck and the tablet can no longer boot successfully. There is an endless loop with following Error messages for a few milliseconds:

E:failed to mount/cache (Ivalid argument)
E:Can't mount /cache/recovery/last_locale

Now I wanted so badly to use Ubuntu instead of the Android "spy system", but now the tablet is just junk.

Is there someone who can help me so that I don't have to throw the tablet away?
:crying_face:

@applee I'm still here and waiting for substantive replies .....