For a vtiger to berliCRM migration we do not provide any migration instructions or automatic migrations scripts but we offer our paid support. Presumably we cannot write any instructions that always work because there are too many vtiger versions out there. It gets even more complicated if a vtiger version migration was been done before and/or there are local modifications on the vtiger installation (what is usually the case). Therefore, it depends on the individual case, how much effort is needed to migrate. In many cases a 3h workload is sufficient … but … it depends :-/