The T-800 is one of the most formidable cyborgs ever shown on the silver screen. This classic action villain played by Arnold Schwarzenegger is portrayed as being extremely tough in the Terminator films but not unkillable. In a hypothetical scenario is it possible to defeat this metal monster? Yes but only if the right tactics are utilised.
Going head to head up against such a dangerous machine would be suicide. In Terminator Salvation even an experienced soldier like John Connor is mortally wounded in such an attempt. One weakness is that the T-800 has a battery life like all other cyborgs. The human could simply flee and start an anonymous life somewhere else in the hope that the Terminator will eventually power down before it finds them.
In the battle between the humans and Skynet time travel is an important weapon. It is used by both sides to gain victory. The human could read Wikipedia pages on the subject to better understand the nature of time travel and then utilise it as a tool to fight the Terminator. For example, they may send a message back to their past self to gain the upper hand.
Like all other pieces of modern tech the original T-800 can be destroyed with an EMP. The main issue is creating one in the first place. Also, more advanced incarnations of the Terminator such as the T-X have been shown to be immune to such attacks.
In the Terminator films the T-800 is usually destroyed by being lured into a trap. In the first movie this involved allowing it to crawl into a crushing machine. Therefore the simplest and most effective way of surviving is by setting up such a trap. The downside is the human will have to use themselves as bait.