Setup a replication slave without stopping master

[Claudio Nanni]

All, Happy New Year, and let's hope somebody tries to stop the killing in
gaza.

I need to setup a replication slave off a master that is currently
production and not stoppable or lockable(possibly).

Do you have any idea on how to setup the slave with minimum or no impact on
the master?

The database is about 80GB.

Thanks

C.