Unique credit score issue - how to boost?

[Lisa M. Super]

I’ve been actively working to repair my credit for the last two years. My debt to credit ratio is down, my payments are on time. What’s really dragging down my score are the late payments shown on my record for debts I’ve already paid off, but are still showing on my report.

Any suggestions for how to get rid of these to get me a boost would be much appreciated.