How to remove SSRS users and permissions programmatically?

Hi,

Im trying to remove users who already have browser access from SSRS using rs.exe or SOAP.

I managed to add users using rs.exe and a rss file however I dont see how I can use set policies to remove a user completely or just the access they have. Ideally remove them completely.

Has anyone had any luck with doing this?

I will actually be doing all this in a SSIS package which will be refreshed daily with new users and remove inactive users.

Thanks