MUST catch cat.

This is my first post here, so forgive me if its in the wrong category.

I have an elderly woman who volunteers at my job, who has moved from a big house to a one bedroom apartment. She has 2 cats, and can only take 1 with her. I am taking her other cat, who is a black siamese (she thinks). She has lived in the new apartment for one month now, and just goes back to the house to feed the other kitty every day. She has attempted to put him in a cat carrier every day and he just won't go. I don't think she wants to be aggressive because she is older and probably not that strong. They are having an estate sale pretty soon so she thinks he will run away after that. 

   She doesn't want anyone to help because she thinks they will scare him away. Please please please let me know if you have any suggestions. I want to help her but I just don't know what to do and neither does she.

Thanks!!!

The easiest way to do this would be to trap him in a humane trap. Call around local vets, TNR groups or animal rescue groups in your area and ask if you can hire/borrow one from them. Put the uncovered trap in the spot you usually feed the cat, put some of his favourite food in the trap and when he goes in the trap will shut. If he is very nervous you can cover the trap with a blanket while you take him to his new house. If he's been handled before he shouldn't freak out to much.

If you Google humane traps you'll see what I mean. There are lots of videos on Youtube which demonstrate how to use them.

Make sure you keep him indoors for at least a month when he gets to his new home, or he'll try to get back to his old home again.

Good luck.