[TYPO3-install] upgrading 3.7.0 to 4.0.2, paths messed, localconf.php not found

[Michael Gabriel]

im trying to upgrade a 3.7.0 install to 4.0.2
after unpacking and adjusting the symlinks, the install tool keeps telling
me that the localconf.php aint found.
after investigating a bit i found that the path detecting is doing weird
things
all the tutorials(even those updated to v4) still show it possible to
extract typo3 into the web folder. but the install tool doenst seem to
understand that !?!?!?!

/home/httpd/vhosts/domain.com/httpdocs/typo3_src/typo3conf/: PATH_typo3conf
/home/httpd/vhosts/domain.com/httpdocs/typo3_src/: PATH_site
/home/httpd/vhosts/domain.com/httpdocs/typo3_src/typo3/: PATH_typo3
typo3/: TYPO3_mainDir
/home/httpd/vhosts/domain.com/httpdocs/typo3_src/typo3/install/index.php:
PATH_thisScript

thisScript is right an ok. then init.php does strip install/ from the
MOD_PATH

and then the mainDir
define('PATH_site', substr(PATH_typo3,0,-strlen(TYPO3_mainDir)));    // Abs.
path to directory with the frontend (one above the admin-dir)

so that still leaves me in the typo3_src folder and NOT in the httpdocs
where the typo3conf is located !?!?!?