modify existing PHP image upload to preserve GIF animation

I have a PHP file that uses the GD library to resize and crop images that the user wants to upload to their profile. I need someone to modify the file to check and see if the file is animated, and if it is animated, then resize the thumbnail (but skip the cropping) and preserve the animated frames. I've found several variations of instructions on how to accomplish this, however i'm not getting it to work at this time and need some assistance. I don't have a very large budget, unfortunately. My server does have imagemagick installed, should you prefer to do it that way. I will attach the current file that processes the image uploads, and you should be able to modify the file, allow me to test on your server, and I will release payment, you'll send the updated file which should hopefully work after overwriting the old file on my server, and then I'll leave you a great feedback :)