Hi Nat,
Platform lookup (investment_app_platform) you mentioned is System provided one. Hence you might not be able to De-Activate the existing lookup values. However you can add the new lookup values to this lookup.
There are 2-ways you can update the existing values as per your requirements.
1. Rename the existing values from DB side.
2. De-Activate the unwanted lookup values from DB side.
P.S. However the issue with doing either of these 2-above work around solutions from DB is - as this is System lookup whenever your system gets upgraded these lookup values will be override with the system values.you'll have to manually make the changes again.Updating/customizing any system provided features/functionalities will create discrepancies down the line.
Hence Ca will not recommend these kind of solutions and at the same they won't support as well.
However there are 2- other ways to attain your requirement -i.e.
1. Please avoid using this system lookup and create your own Static lookup with the values you are looking for, this would be more easy & hassle free in your case.
2. Please create a Dynamic lookup which will be retrieving ONLY the lookup values you wanted from Platform lookup (investment_app_platform). This way you still using system feature & at the same time you are attaining your requirement.
you can create a Dynamic Query lookup using the below query(considering you wanted to show only 2- lookup values, if you wanted more lookup values you could add them to below query)
select id,name from cmn_lookups_v where lookup_type ='INVESTMENT_APP_PLATFORM'
and language_code = 'en' and name in ('Windows','Macintosh')
Best Regards
Jagadeesh