Hi there OK Nearly There and welcome to the forum
Given you have been in your DMP for a while your creditors will almost certainly accept 50% of the outstanding balance to settle the remaining debt. However they might accept less. My suggestion is to offer 30% initially and see what they say. Then you can then always up the offer if need be. The trick is be coy about where the money is coming from. I recommend that you say it is from a family member. That way of a creditor rejects your first offer you can always say you went back to the familiy member and they were able to offer a little more.
You can find more info about settling DMP debt early here: How to settle a DMP early