Hello I'm using Mamboard 1.2.2 on Joomla 1.0.13 php 5.2.4, how to migrate to Fireboard?

It should work the same as Joomlaboard.

I know ...but how can I do the upgrade?
just like that? no mysql updates?
any files to keep ?

Fireboard runs ALONGSIDE Joomlaboard after it is installed. No sccripts to manually run. At the end of the install some information is imported into FB but the Joomlaboard installation remains untouched. Should the install not work you can uninstall Fireboard without harming your Joomlaboard install. I cannot speak with any certainty about Mamboard except that I'm assuming that was Simpleboard's next name (?). However before attemmting this I would backup EVERYTHING!!! Better still a new version of FB is very near on the horizon.It (hopes) to address many issues that are plaguing it right now. You might want to wait for that.

I will wait. I can't lose messages, us 45% on site visits are based on forum visits.
and I'm speaking about 1k6 visits daily...
Thank you very much!