Logstash v5 installing filter-multiline plugin

i'm trying on my Test environment tne new elastic stack v5
when updating logstash i got the error message that the logstash-filter-multiline plugin is not built-in any more
i downloded from git-hub the plugin (manually)
now i'm trying to install the plugin on my offline machine
the procedure i've found online were really complecated
can anyone simplify it for me
what are the steps i need to do in order to install this plugin ?
thank you!

The multiline filter plugin has been deprecated. It is recommended to switch to the multiline codec plugin instead. If you are using FileBeat you can also perform the multiline processing there.

Hi , thanks for your reply ,
But multiline as a codec in the input has been known to cause some issues (not reading the last line and so ) that's why i used it as a filter
Do you know if this issues were fixed ?