sybrand (6/6/2014)
This is the Important part and the way to shrink the Transaction log is to set the Recovery to Simple in properties, then go to Shrink File and select log file (not data) this can be quick if you have done the full backup but it can also take some time depending on a couple of things that I am not going into now, but leave it and let it finish. When this is done go back to properties and set Recovery back to full.
No need. You can shrink the log once you've run a log backup. Breaking the log chain is not necessary. You also didn't mention the requirement to run a full/diff backup after switching back to full recovery.
Also
when the log backup is done SQL writes the data to Database and it is important to know that no rollback would be possible after that.
That's not true.
All a log backup does is write the portion of the log to a backup file and then mark that portion of the log as reusable. Log backups don't write to the data file. Rollbacks aren't possible after a transaction commits, nothing to do with log backups.
http://www.sqlservercentral.com/articles/Administration/64582/
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability