Hi.
It is not possible directly on TV, but there is much convenient way.
Insert USB stick.
Go to Settings - Channels - Copy channels (at the bottom)
Copy to USB
Download and install ChanSort utility http://sourceforge.net/projects/chansort/
On USB you should find file like GlobalClone00001.TTL (at least on 40LF630 models) so open it in ChanSort
Delete, move, rename, renumber channels as you like, then save/overwrite with deleting unsorted channels.
Put the USB back to TV and copy channels list back to TV. (Dont forget to select correct USB device if you have more devices connected)
It should restart after while and now you should have nice program list.
I hope this helps.