How to delete year members in Hyperion Planning application?

Hi gurus,

I need to delete year members in the  year dimension. We have this members in the year dimensions:

FY06: We need deleted it.

FY07: We need deleted it.

FY08: We need deleted it.

FY09: We need deleted it.

FY10: We need deleted it.

FY11: We want to keep it.

FY12: We want to keep it.

FY13: We want to keep it.

FY14: We want to keep it.

FY15: We want to keep it.

FY16: We want to keep it.

FY17: We want to keep it.

FY18: We want to keep it.

FY19: We need deleted it.

FY20: We need deleted it.