updating Mailwizz to latest version, resolving stalled bounce server

We have an immediate problem in that the bounce server is stuck on cron-running on the Mailwizz email management program. The "quick fix" using emergency actions on the master panel does not solve the issue, and more advanced solutions involve SSH and other skills which I lack. As well, there is a recent posting of an update of the program, and because the files are so large, we cannot do this except at the SSH level. You should understand Mailwizz and the basic issues of access/management to solve this assignment, which is urgent as we cannot safely send out emails until the bounce server is operating properly (and we do not wish risks of spam complaints).