Check out my latest 2 videos, which will cover both migration scenarios using my AzLogDcrIngestPS PS-module:
Side-by-Side Migration (new table, new naming convention)
Re-use existing table – Migrate to DCR based format
If you want to learn more about AzLogDcrIngestPS (github), check out the link here
AzLogDcrIngestPS has already been download +150K times – check it out at Powershell Gallery