How do I clear cells in EPM Planning when the value entered is 0

Our EPM Cloud Planning application is huge and needs to be sorted. One of the things our Support 'Partners' has suggested is to 'Export Level 0 data and see if data is filled in with 0. Sometimes database is filled with 0 data which needs to be cleared.'

That is easier said than done. Our L0 data is way to big to fit in a spreadsheet, never mind analyzing millions of rows of data! So I would like to simply clear cells filled with 0. But… how might a body do that? Any suggestions please?