Initial impetus for upgrade was 5.04 instal broke so I could not access assets or instantiate an asset from inside an entry page. Turns out the last asset I uploaded was to big or clumsy to render a thumbnail in the assets page, so I got a communications error or internal server error.
Determine version of existing instal. Use FileZilla to change mt-check.cgi to mt-check-unsafe.cgi in www.rako.com/mt/ sub-directory. No, really. In browser run www/rako.com/mt/mt-check-unsafe.cgi
See that MT6 is pay-only or some free crap that will screw you and is crippled. Find MT5.2 on home computer, saved from previous instal.
Create mt-5.022 sub-directory. Copy files from local computer.
Copy mt-config.cgi to new sub-directory. Nothing works. Realize have to change contents of mt-config.cgi to show new instal directory, /mt-5.022/
Nothing works, realize that Movable Type comes pre-broken. Set all cgi files in mt-5.022 to 755 using FileZilla to change properties of batch of all the cgi files.
Kinda works and changes database. User interface all schwaked and over-written. Obvious CSS (cascading style sheets). Realize MT5.2 also needs the new mt-static directory. Instal as www.rako.com/mt-static-5.022.
Realize mt-config also has a pointer to the static directory, change mt-config.cgi. Does not work until re-log in from scratch.
Figure about time to read directions, so look at this support page. Copy over support directory from /mt-static/ and themes new stuff from /mt/
Things look OK but whole problem started because assets would cause "internal server error". By uploading new asset it seemed to fix-- I assume MT corrupted its own database. New asset fixed, perhaps in conjunction with upgrade to 5.2. (No, only a coincidence, had to try and try with filters to get big picture displayed so I could delete it.)
Erased www.rako.com/mt/ and www.rako.com/mt-static and this page got scwacked, Changed hard-coded path in suffer.css stylesheet to new mt-static-5.22/ path.