How to Grant Temporary Access to Elancer

I need to give permission to elancer working on code. How do I do that without sharing my passwords? Can I create a temp one for him? Here's his message:

I need the ftp access to test the code, i am not able to set it in local as the pop spacing of width and all are on the main pages where the popup is called.

So what's the procedure to give him access to my ftp?