Movie synch problem

I'm trying to get a movie I've purchased onto my iPod Classic. When I drag it to my iPod device, it gives me the message:

The iPod “my ipod” is currently linked to another iTunes library on “computername”.

In order to copy the movie “moviename” to this iPod, you must link this iPod with this iTunes library.

It also says doing this will remove 8 of my videos already on my iPod, which I obviously don't want.

How can I get the movie on my iPod without the other videos being deleted?

Any help would be very much appreciated. Thank you!