How old are the debts? It definitely looks better when they’re paid. I read some lenders will actually make you pay all debt before offering you a mortgage. If they are old enough then you could just wait for them to drop off your report.
I would start by doing a debt validation request through the credit bureaus. If the collection agency cannot validate the debt, then they cannot continue collection and they have to delete it from your report.
If they validate, then try to settle. I’m not sure if you are aware, but collection agencies pay pennies on the dollar for those accounts. So you can definitely en up paying 50% or less of what you originally owed. Ask for a deletion and written proof of all this. Don’t call them, always communicate with them through regular mail.
Have you received any settlement offers?