Take a look at the back of the plate and note how the wiring appears. You should see one of two colour codes of wiring depending on when the house was last wired: blue or black is neutral, brown or red is live, and green/yellow is earth. It may be a good idea to take a photo at this point. This will help you recall which terminal each wire should be connected to on the new outlet at a later stage. Loosen and remove the screws connecting each cable to the existing faceplate. If heat damage to any of the cables is obvious, cut the damaged end of the wire off and then strip back a little insulation.