I want to change the ownership of a directory ONLY.
my id
id1 owns the files under the /mypath/bin
but /mypath/bin is owned by id2
If i log into id2
I can't do
chown id1 /mypath/bin
Sorry but on most types of UNIX, you need to be the root user to do that. It's a security feature (directories included).
Imagine a shared environment in, say, a university. You don't like "bob" very much so you create a bunch of dodgy files containing unsavory pictures, bomb recipies and other antisocial things and drop it into /tmp. You then chown to the files to bob and then send an email the head of department 
If it's something you need to routinely do though and it's on the same name files every time, talk to your administrator about being given special rights to run the following command:
sudo chown id1 /mypath/bin