The aim of this script is to make process of upgrade repeatable so you can easily repeat it on you local instance and run it also on staging and finally on production instance.
Its tested and written to work only with composer based TYPO3.
Create subdirectory in your TYPO3 root (for example .upgrade) and inside this folder run:
composer require sourcebroker/typo3-upgrade
Basically the script search for branches with name "upgrade_*" switch to them and run commands (look for typo3-upgrade.php for more insights).
If you have some project specific SQL then put it in .upgrade/config/project/[branch part].sql (for example .upgrade/config/project/76.sql)
If you have some instance specific SQL then put it in .upgrade/config/instances/[instance name]/[branch part].sql
The [branch part] is taken from branch name. If branch name is "upgrade_76" then [branch part] is equal to 76.
The [instance name] is taken from INSTANCE env var. Make sure its set in .env file of your project.
Run upgrade in your TYPO3 root directory
./.upgrade/vendor/bin/typo3-upgrade.php
See https://github.com/sourcebroker/typo3-upgrade/blob/master/CHANGELOG.rst