The steps are a little easier to follow on the blog post I made:
If your project is called MyProject, the directory to look at is in MyProject/Binaries/IOS/Payload/
In the Payload folder, find MyProject-IOS-Shipping.app. Right click the file and select Show Package Contents. Copy or Move all files from MyProject-IOS-Shipping.app to MyProject.app (also in the Payload folder).
After copying/moving all the files, re-sign MyProject.app using the Terminal command from the Output Log. Then repackage in an ipa and you’re good to go!