When you say, in step 4, to truncate the log file, do you mean simply to do a

DBCC Shrinkfile (name = 'databaselog', TRUNCATEONLY)?

And then in step 5, switch to SIMPLE mode, and do the same again?

Or do you mean something different by "truncate the log file"?

(You can't do a "BACKUP LOG WITH TRUNCATE_ONLY" in SQL 2008, that backup flag has been removed.)