We do not have a way to delete data which has entered Analytics.
That said, there are some workarounds which sometimes are suited to specific cases, for example if you have fired some revenue value which is more than actual conversion, then you may upload a Data Source file with revenue in negative, so as to reduce the originally uploaded revenue value.
Or, in case of GDPR requests you can delete some user specific data - if you have mapped it correctly in Experience Cloud.
However, if your situation does not fall in either of the two conditions and you necessarily need to delete the data as it is hampering some important experience or is business critical, then you may reach out to Adobe Consulting Team - who may help explore possibilities, this will be a paid engagement.
Your query is more suited to Adobe Analytics forum (link below). Coming to your question, for future hits, you can use Processing Rules to set the correct value for your variable. Refer to the documentation onCleaning up Values in a Report.For past data, you can create a sub-report using Classification variables to show correct values in your report. To delete the values, however, you will have to contact your Adobe Analytics consultant or reach out to the client care team.
Hope this helps. Feel free to explore Analytics forums for further information on your query.