"The Dalek Invasion of Earth" is a six-parter from the English TV series Doctor Who. It is a very popular part of the series and had its first run in 1964. There's even a remake which was shown in theatres.

For the series' 40th anniversary the BBC released a special DVD series which included digitally remastered versions of the episodes. Some of the outdated special effects were replaced by CGI effects.
In the DVD's menu you're able to choose whether you want to see the original effects or rather the modern CGI effects.

Part 1
10.52
The shot of the Battersea Power Station was replaced with a modern CGI animation.
(No difference in time.)

16.06
The Daleks' UFO is flying over the city. The newer CGI effects were generated so that they remind you of the old sci-fi movies from the 50's.
(No difference in time.)

16.23
A few more shots of the UFOs were replaced with CGI animations.
(No difference in time.)

Part 3
7.16
Ditto. In the CGI animation it passes the memorial on Trafalgar Square.
(No difference in time.)

Part 4
14.01
The Daleks' UFO can be seen in the sky.
(No difference in time.)

14.22
Thanks to the new CGI effects the UFO fires at a truck. After the explosion it glows a little.
(No difference in time.)