The only thing I would add is start small, test it out for performance and monitor what’s going on.

When I had started at a place about 4 years ago I implemented some of the maintenance jobs that I do everyhwere (including backup history removal) and I kicked off a history cleanup. Without thinking I just put the date I wanted to delete until (wanted to keep msdb small, didn’t really need that much history so went with 1 month rolling window)… Well there was a LOT of data to delete and it caused some significant performance issues which caused some really fun looking blocking chains.

This was on SQL 2000 and the code definitely changed (it used a cursor in 2000.. you can look at the difference if you do a helptext on the proc in 2000 and then in 2005/2008.. sp_helptext ’sp_delete_backuphistory’). Even in 2005, while it is now performing set based work it is still doing all of the deletes in one transaction. If you perform a lot of backups (log backups, anyone?) there can potentially be a lot of data in that table.