How do I delete pipelines I no longer need?

[Bruce]

Delete option please?

[Daniel Santos]

Hi @Bruce

If you are talking about the build results, that is not possible.
If you are just referring to the ability to trigger builds, you can disable it by Repository configuration  >> Pipelines >> Settings >> Enable pipelines toggle.

You can find more details about this on Aneita Yang's comments on [BCLOUD-17074] Delete pipeline.