RVSC48 (9/29/2016)
Or, have not done this in a while, in ssms, go the properties of the database on the Primary server, then go to Transaction Log Shipping, and uncheck the "Enable this as a primary database in a log shipping configuration" - this should completely remove all log shipping from the database. It will also, supposed to, remove the backup, copy, and restore jobs from both the primary and secondary automatically.
Unfortunately, the primary (former) server is no longer available and has been decommissioned.