re-load from ECC6

Weu2019re on BI7, but using the old BW 3.x Dataflow, no new BI7 Dataflow.

Because of the data quality problem, I would like to delete all the Request from the existing data model (i.e InfoCube, Aggregate, ODS, Master Data, PSA) and perform the full load for all this again.

1.) For InfoCube, I will right-click the InfoCube ->Manage ->Request tab, then select the Request and click on the Delete button manually.

2) For Aggregate, in InfoCube ->Roll Up tab, click on Aggregates button, then open the InfoCube, then click on Deactivate button. (after the re-load, I need to click on Activate button again)

3) For ODS, I will right-click the ODS -> Manage ->Request tab, then select the Request and click on the Delete button manually.

4) PSA, I will right-click on each Datasource ->Manage, then select the Request and click on the Delete button manually.

Questions:

A) What about the ODS Change Log table? How can I delete them?

B) What I understand is Master Data will always be overwritten. So there is no need for me to delete the data for each Master Data correct? Because when I re-load all the data from ECC6, all the data in the Master Data will be overwritten, correct?

C) Is there any other thing that I need to take care in order for me to re-load all the data again from ECC6 into BW?