Yes, and no! For one you need to learn to code in MQL properly and two you need to apply good coding practices.
Since, you are not a coder (and that is the reason you hired a someone on the Freelance section), I don't believe you will have the necessary skills to make the required changes and code it correctly.
is it worth putting it back on freelance and see if someone is willing to try and clean it up a bit?
Well, post #1 by @whroeder1 is still a valid answer to that! The only difference now, is that you understand that quality coding has a higher price tag and that the better coders don't necessarily hang out at the Freelance section.
That is up to you! You may get someone that knows what he is doing or you may not.
Offering a high price does not filter out the "bad" coders either, because you will have no idea who you are getting!
Hence why the good coders rely on word-of-mouth instead!
thanks you for your help