I have recently hired someone to create a website for me. It is a wordpress ecommerce site with many custom features, many products and many pages. We have been trying to get it right for a few months now and there are some issues that he is not capable of fixing. I would like to get someone else to finish the site for me because i can not keep paying more and more to this company while i get no results. I am now going to ask that they send me all of the files for the website.

My question is... Is there anything in particular that i should make sure i receive from him to ensure someone else can continue to finish the site? are there any special files that the new designer will need to make his life easier? And are there any tricks that i should look out for that they might want to do to ensure that only they can work on the website?

Thank you in advance for your help.