This is for Community Version 6.5.x. I was looking for an answer and was about to ask here when I eventually figured it out on my own. In case someone else has a similar question in the future Id like to share my solution here.
The drop down menu is build for all modules so changing the item order within the menu is not possible for a single module. Feel free to correct me here if you know more.
Its build from the code in ./include/ListView/ListViewDisplay.php. Within that file search for 'buildActionsLink'. To change the order of the items in the pull down menu, change the order in which they are created within this function. E.g. in my case I wanted to move 'delete' further down so users are less likely to delete an entry (was a user request). For this I moved the delete code (it should be marked with a comment) to the end, right before the for loop for the 'actionsMenuExtraItems'.